Trial stimulation systems

ABSTRACT

A trial stimulation system includes a disposable trial electrical stimulator that, in some examples, is sterilized for a single use in a stimulation trial of one patient. Additionally, systems for securing a disposable trial stimulator to the body of a patient are described, which may function to improve the durability of the system during the trial period and reduce the risk of damage or malfunction to the system due to lead/electrode dislocation and/or off-label uses like showering or bathing with the trial stimulator still secured to the body.

This application claims the benefit of U.S. Provisional PatentApplication Ser. No. 61/638,938, filed Apr. 26, 2012, and entitled“TRIAL STIMULATION SYSTEMS,” the entire content of which is incorporatedherein by reference.

TECHNICAL FIELD

The disclosure relates to medical devices.

BACKGROUND

A variety of medical devices are used for chronic, e.g., long-term,delivery of therapy to patients suffering from conditions that rangefrom chronic pain, tremor, Parkinson's disease, and epilepsy, to urinaryor fecal incontinence, sexual dysfunction, obesity, spasticity, andgastroparesis. As an example, electrical stimulation generators are usedfor chronic delivery of electrical stimulation therapies such as cardiacpacing, neurostimulation, muscle stimulation, or the like. Pumps orother fluid delivery devices may be used for chronic delivery oftherapeutic agents, such as drugs. Typically, such devices providetherapy continuously or periodically according to parameters containedwithin a program. A program may comprise respective values for eachparameter in a set of therapeutic parameters specified by a clinician.

Chronic implantation of a stimulation generator and one or more leadsfor delivering stimulation therapy to a patient may be preceded by atrial period. The trial period ordinarily has a prescribed maximumduration, but sometimes is exceeded by the patient or the physician.During the trial period, a clinician evaluates the efficacy ofstimulation in alleviating the patient's disorder to determine whetherthe patient is a good candidate for chronic implantation. The trialperiod ordinarily involves implantation of a temporary or chronic lead,and percutaneous connection of the lead to an external trial stimulator.Often, connection of the lead to the trial stimulator involves extensivesubcutaneous tunneling of the lead to a percutaneous exit site.

SUMMARY

Examples according to this disclosure are directed to trial electricalstimulation systems for delivering medical therapy. A trial stimulationsystem may include a disposable trial stimulator that is sterilized fora single use in a stimulation trial of one patient. The followingexamples also include a device for securing a disposable trialstimulator to the body of a patient, which may function to improve thedurability of the system during the trial period and reduce the risk ofdamage to or malfunction of the system due to lead/electrode dislocationand/or off-label uses like showering or bathing with the trialstimulator still secured to the body.

In one example according to this disclosure, a medical system includes adisposable trial electrical stimulator, at least one percutaneousstimulation lead, and an electronic programming device. The disposabletrial stimulator includes a single user interface integral with thetrial stimulator. The at least one percutaneous stimulation lead isconnected to the trial stimulator. The electronic programming device isconfigured to wirelessly communicate with the trial stimulator toprogram the trial stimulator to deliver stimulation therapy via the atleast one percutaneous stimulation lead. The user interface isconfigured to cause the trial stimulator to be capable of wirelesscommunications with the electronic programming device and to turn offstimulation being delivered by the trial stimulator.

In another example, a disposable trial electrical stimulator includes apulse generator, a lead coupler, and a processor. The pulse generator isconfigured to deliver electrical stimulation via at least onestimulation lead connected to the trial stimulator. The lead coupler isconfigured to connect the at least one stimulation lead directly to thetrial stimulator without any intervening lead connection devices. Thelead coupler is also configured to connect a plurality of types ofstimulation leads directly to the trial stimulator without anyintervening lead connection devices. The processor is configured tocontrol the pulse generator to deliver the electrical stimulation viathe at least one stimulation lead. The trial stimulator is sterilized.

In another example, a system for securing a disposable trial stimulatorto a body of a patient includes a patch and a holster. The patchincludes a first major surface at least partially covered with anadhesive configured to adhere the patch to the body of the patient. Theholster is connected to a second major surface of the patch. The holsteris configured to receive the trial stimulator.

In another example, a method includes implanting at least onepercutaneous stimulation lead to deliver stimulation to a target tissuelocation and connecting the at least one percutaneous stimulation leadto a disposable trial stimulator comprising a single user interfaceintegral with the trial stimulator. The user interface is configured tocause the trial stimulator to be capable of wireless communications withthe programmer and to turn off stimulation being delivered by the trialstimulator. The method also includes programming the trial stimulator todeliver stimulation via the at least one percutaneous stimulation leadwith an electronic programming device configured to wirelesslycommunicate with the trial stimulator, delivering stimulation to thetarget tissue location via the at least one percutaneous stimulationlead with the trial stimulator for a trial period of time, and disposingof the trial stimulator after expiration of the trial period of time.

In another example, a method includes implanting a percutaneousstimulation lead to deliver stimulation to a target tissue location andconnecting the percutaneous stimulation lead directly to a disposabletrial stimulator via a lead coupler integral with the trial stimulator.The lead coupler is configured to connect a plurality of types ofpercutaneous stimulation leads directly to the trial stimulator withoutany intervening lead connection devices. The method also includesprogramming the trial stimulator to deliver stimulation via thepercutaneous stimulation lead with an electronic programming deviceconfigured to wireless communicate with the trial stimulator, deliveringstimulation to the target tissue location via the percutaneousstimulation lead with the trial stimulator for a trial period of time,and disposing of the trial stimulator after expiration of the trialperiod of time.

In another example, a method of securing a disposable trial stimulatorto a body of a patient includes implanting a percutaneous stimulationlead to deliver stimulation to a target tissue location and adhering afirst major surface of a patch at least partially covered with anadhesive to the body of the patient. A holster is connected to a secondmajor surface of the patch and the holster is configured to receive thetrial stimulator. The method also includes inserting the trialstimulator into the holster and connecting the percutaneous stimulationlead to the trial stimulator.

The details of one or more aspects of the disclosure are set forth inthe accompanying drawings and the description below. Other features,objects, and advantages of the examples of the disclosure will beapparent from the description and drawings, and from the claims.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a conceptual diagram illustrating an example trial stimulationsystem according to this disclosure.

FIGS. 2A-2C are conceptual diagrams of a number of views of the exampletrial stimulator of the system of FIG. 1.

FIG. 3 is a conceptual diagram illustrating another example trialstimulation system according to this disclosure.

FIGS. 4A and 4B are conceptual diagrams of a number of views of theexample trial stimulator of the system of FIG. 3.

FIG. 5 is a functional block diagram illustrating an exampleconfiguration of the implantable medical device (IMD) of the systemsshown in FIGS. 1 and 2.

FIG. 6 is a functional block diagram illustrating an exampleconfiguration of the external programmer of the systems shown in FIGS. 1and 2.

FIG. 7 is a flowchart illustrating an example method of using adisposable trial stimulator.

FIGS. 8A-8C are conceptual diagrams illustrating an example system forsecuring a disposable trial stimulator to the body of a patient.

FIGS. 9A-9C are conceptual diagrams illustrating another example systemfor securing a disposable trial stimulator to the body of a patient.

FIG. 10 is a flowchart illustrating an example method of securing adisposable trial stimulator to the body of a patient.

DETAILED DESCRIPTION

This disclosure is directed to electrical stimulation therapy deliveredvia a trial stimulator during a trial stimulation period. Prior to adecision to implant a chronic neurostimulation device, e.g. a spinalcord stimulation device used to deliver therapy for chronic pain, a deepbrain stimulation (DBS) device used to deliver therapy for any of avariety of brain disorders, a gastric stimulation device used to delivertherapy for gastroparesis or gastro-intestinal disorders or obesity, ora pelvic floor stimulation device used to treat urgency and/or urinaryincontinence, pelvic pain, sexual dysfunction, or other disorders,patients typically undergo an evaluation phase of 1-3 weeks using anexternal trial stimulator connected to one or more stimulation leads.Current trial stimulation systems share a number of negative attributes.

Current trial stimulation systems include a reusable trial stimulator.Some such reusable trial stimulators include, not only the electronicsand power source necessary to deliver stimulation therapy via one ormore leads, but also a number of user input/output (I/O) controls thatare necessary for operation of the system. Because current trialstimulators are reusable, such devices generally cannot be sterilizedbetween trials and are therefore kept out of the sterile field duringthe surgical procedure in which the leads of the trial stimulationsystem are implanted and initial stimulation testing takes place. Suchreusable trial stimulators, which are not designed to be sterilized, arekept out of the sterile field during surgery to prevent crosscontamination of blood or other bodily fluids between different trialsemploying the same stimulator.

It has been generally considered that designing the trial stimulator tobe reusable is an advantage, as it may reduce waste and costs. However,the inability to sterilize the device and the requirement that thedevice be outside of the sterile field during surgery, may lead toseveral consequences that may outweigh the benefits of reusability. Forexample, during intraoperative stimulation testing of a trialstimulation system including a reusable non-sterile trial stimulator, awired connection is required between the sterile components of thesystem, e.g. leads and the stimulator. This wired connection must crossthe sterile field perimeter. The inability to maintain the integrity ofthe sterile field during surgery may allow potentially harmful microbesto travel into or out of the sterile field, which may, in turn, lead tocomplications such as contamination and/or infection.

After surgery during the at-home phase of the stimulation trial, currenttrial systems commonly employ leads, which are connected to a leadextension and/or adaptor connected to a trial stimulator that is wornexternally on the clothing or a lanyard. Externalization of the trialstimulator, as well as the necessity for the lead extension and/oradaptor, may increase the likelihood of inaccurate tests results becausesystem wires can become hung up on clothing or the environment (doorknob) or otherwise interfered with, potentially causing dislocation ofthe stimulating electrodes within the body of the patient.

Another disadvantage of current trial stimulation systems is the mannerin which users interact with the system to control stimulation therapyor otherwise interact with the trial stimulator. In some currentsystems, as noted above, the trial stimulator includes a number of userinput/output controls that are necessary for operation of the system.However, as the trial stimulator in some such systems is commonly heldor secured to the back of the patient, it is inconvenient or impracticalfor the patient to interact with the I/O devices integral with thestimulator. The inclusion of I/O devices integral with the trialstimulator also prevents maintaining the sterile field during surgery,as it may be necessary to interact with such devices duringintraoperative testing of the stimulator. Additionally, some currenttrial stimulation systems utilize programming devices for modulating thetherapy, which, while separate from the trial stimulator, mustnevertheless be directly next to or very near the stimulator tocommunicate with it. Again, due to the placement of the trial stimulatoron or near the back of the patient, such programming devices may beinconvenient or impractical to use.

In view of the foregoing challenges, examples according to thisdisclosure are directed to trial stimulation systems that include adisposable trial stimulator that is sterilized for a single use in astimulation trial of one patient. The following examples also include adevice for securing a disposable trial stimulator to the body of apatient, which may function to improve the durability of the systemduring the trial period and reduce the risk of damage or malfunction tothe system due to lead/electrode dislocation and/or off-label uses likeshowering or bathing with the trial stimulator still secured to thebody.

In one example according to this disclosure, a medical system includes adisposable trial stimulator, at least one percutaneous stimulation lead,and an electronic programming device. The disposable trial stimulatorincludes a single user interface integral with the trial stimulator. Theat least one percutaneous stimulation lead is connected to the trialstimulator. The electronic programming device is configured towirelessly communicate with the trial stimulator to program the trialstimulator to deliver stimulation therapy via the at least onepercutaneous stimulation lead. The user interface may include, e.g., abutton, rocker switch, slider switch, or rotary dial switch and isconfigured to cause the trial stimulator to be capable of wirelesscommunications with the electronic programming device and to turn offstimulation being delivered by the trial stimulator.

Stimulation leads referred to in this disclosure as “percutaneous” leadsmay include leads that are not fully implanted within the body of apatient and, instead, are arranged partially implanted through anincision in the skin. As such, a percutaneous lead does not necessarilyrefer to the surgical process by which the lead is partially implantedwithin the body, e.g., percutaneously or surgically via a laminectomy orlaminotomy. For example, a percutaneous lead, as referred to in thisdisclosure, may be surgically placed via a laminectomy or laminotomy.For example, a paddle lead may be employed in a trial stimulation systemthat treats chronic pain via spinal cord stimulation, which lead mayneed to be surgically implanted. Nevertheless, the physical arrangementof such a lead in a trial system may be only partially implanted throughan incision in the skin. In this manner, “percutaneous” may refer to thephysical arrangement of the lead as partially implanted through the skinof the patient versus the manner in which the lead is initially placedby a physician or other clinician.

In another example, a disposable trial stimulator includes a pulsegenerator, a lead coupler, and a processor. The pulse generator isconfigured to deliver electrical stimulation via at least onestimulation lead connected to the trial stimulator. The lead coupler isconfigured to connect the at least one stimulation lead directly to thetrial stimulator without any intervening lead connection devices. Thelead coupler is also configured to connect a plurality of types ofstimulation leads directly to the trial stimulator without anyintervening lead connection devices. The processor is configured tocontrol the pulse generator to deliver the electrical stimulation viathe at least one stimulation lead. The trial stimulator is sterilized.

In another example, a system for securing a disposable trial stimulatorto a body of a patient includes a patch and a holster. The patchincludes a first major surface at least partially covered with anadhesive configured to adhere the patch to the body of the patient. Theholster is connected to a second major surface of the patch. The holsteris configured to receive the trial stimulator.

FIG. 1 is a conceptual diagram illustrating an example therapy system 10that delivers electrical stimulation therapy to a patient 14. In theexample of FIG. 1, for illustration, system 10 is configured to managean urgency and/or urinary incontinence disorder of patient 14. Urgencyand urinary incontinence (e.g., an inability to control urinaryfunction) are problems that afflict people of all ages, genders, andraces. Various muscles, nerves, organs and conduits within the pelvicfloor cooperate to collect, store and release urine. A variety ofdisorders may compromise urinary tract performance, and contribute tourgency or incontinence. Many of the disorders may be associated withaging, injury, or illness.

Urgency may originate from disorders of portions of the peripheral orcentral nervous system which control the bladder micturition reflex.Nerve disorders may also lead to overactive bladder activities and/ormay prevent proper triggering and operation of the bladder. Furthermore,urgency or urinary incontinence may also result from impropercommunication between the nervous system and the urethra. In otherexamples according to this disclosure, an example trial stimulationtherapy system may be configured to treat other conditions, including,e.g., fecal incontinence.

In FIG. 1, therapy system 10 includes an example trial stimulator 16,which is coupled to percutaneous lead 18 including electrodes 20A-20Dvia lead extension 22. Trial stimulator 16 is also configured towirelessly communicate with external programmer 24. Trial stimulator 16generally operates as a trial therapy device that delivers electricalstimulation to, for example, a tissue site proximate a pelvic floornerve, a pelvic floor muscle, the urinary sphincter, or other pelvicfloor targets. Pelvic floor nerves include peripheral nerves such assacral nerves, pudendal nerves and associated branches, and dorsalgenital nerves. In some examples, trial stimulator 16 delivers theelectrical stimulation therapy to a sacral nerve of patient 14 togenerate an afferent response that relaxes bladder 12, e.g., to reduce afrequency of bladder contractions.

Trial stimulator 16 may be employed by a physician or other clinician totest the efficacy of stimulation therapy for treating a particularpatient's condition and also to determine parameters or sets ofparameters according to which efficacious stimulation therapy may bedelivered to the patient. Trial stimulator 16 may be employed to teststimulation for a patient for a limited, trial period of time, e.g. anumber of days, a week or more, or longer than a few weeks. After thetrial stimulation period is completed, depending on the results of thetrial, trial stimulator 16 and percutaneous lead 18 may be removed andan implantable medical device (IMD) along with one or more implantableleads may be implanted in the patient to deliver chronic stimulationtherapy over an extended period of time, e.g. over the operating life ofthe IMD.

Trial stimulator 16 provides electrical stimulation therapy to patient14 by generating and delivering electrical stimulation signals to atarget therapy site by lead 18 and, more particularly, via electrodes20A-20D (collectively referred to as “electrodes 20”) disposed proximateto a distal end of lead 18. For example, trial stimulator 16 may deliverlow intensity stimulation (e.g., subthreshold stimulation) and highintensity electrical stimulation therapies to patient 14 to elicitdelayed and immediate physiological responses, respectively. Trialstimulator 16 may also deliver stimulation at intensities between thelow intensity and high intensity stimulation. For example, trialstimulator 16 may gradually transition delivery of stimulation from thelow intensity to the high intensity in increments defined by, forexample, a ramp function, a step function, or a curvilinear function. Insome examples, trial stimulator 16 may modify stimulation therapyintensity and duration based on sensor data and/or patient input. As oneexample, trial stimulator 16 may detect an increased rate of bladdercontraction based on sensor data and then modify stimulation (e.g.,increase intensity) based on the detected increase in bladdercontraction frequency.

Trial stimulator 16 may deliver stimulation therapy to patient 14according to one or more stimulation parameters, which may be includedin stimulation programs and/or program groups. The therapy parametersfor a therapy program that controls delivery of stimulation therapy bytrial stimulator 16 through the electrodes of lead 18 may includeinformation identifying which electrodes have been selected for deliveryof stimulation according to a stimulation program, the polarities of theselected electrodes, i.e., the electrode configuration for the program,and voltage or current amplitude, pulse rate, and pulse width ofstimulation delivered by the electrodes. Delivery of stimulation pulseswill be described for purposes of illustration. However, stimulation maybe delivered in other forms such as continuous waveforms.

As described in more detail with reference to FIGS. 2A-2C, trialstimulator 16 may be configured as a body-worn device that may, in oneexample, be secured to the back of patient 14. Trial stimulator 16 maybe secured to patient 14 in a number of ways, including by, e.g.adhering a surface of the device to the skin of patient 14, e.g., withan adhesive or taping the device to the patient with an adhesive tape.Additionally, FIGS. 8A-9C illustrate systems according to thisdisclosure for securing body-worn trial stimulators, including, e.g.trial stimulator 16, to the body of a patient.

Trial stimulator 16 has an outer housing that is constructed of abiocompatible material that resists corrosion and degradation frombodily fluids including, e.g., a polymeric material including silicone,polyurethane, or other biologically inert polymers. In one example, thehousing of trial stimulator 16 is fabricated from one or morethermoplastics. For example, the housing of stimulator 16 may befabricated from a polycarbonate and ABS polymer blend. In one example,the housing of trial stimulator 16 may be fabricated from Cycoloy®C2950HF PC+ABS from SABIC Innovative Plastics of Pittsfield, Mass. Theproximal end of lead 18 is both electrically and mechanically coupled totrial stimulator 16 via lead extension 24. Lead extension includes leadadaptor 26, which may be configured to connect a number of differenttypes of leads to trial stimulator 16. Lead adaptors included in leadextension 24 may vary from the example illustrated in FIG. 1. Forexample, lead extension 24 may include a lead adapter that is branchedsuch that it is configured to couple multiple percutaneous leads to leadextension 24. Electrical conductors disposed within the lead body oflead 18 electrically connect electrodes 20 to a therapy delivery module(e.g., a stimulation generator) within trial stimulator 16. Although notshown in the example of FIG. 1, trial stimulator 16 may be coupled toadditional percutaneous leads. In one example, trial stimulator 16 maybe coupled to one or more leads including a number of electrodes forsensing physiological parameters related to delivering urgency and/orurinary incontinence therapy to patient 14. For example, trialstimulator 16 may be coupled to one or more percutaneous leads includingelectrodes positioned within the body of patient 14 for sensing animpedance of bladder 12, which may decrease as the volume of urinewithin bladder 12 increases.

Lead 18, and, if provided, other leads coupled to trial stimulator 16,may be percutaneously tunneled through incision 28 to place one or moreelectrodes, e.g. electrodes 20 carried by a distal end of lead 18 at adesired pelvic nerve or muscle site, e.g., one of the previously listedtarget therapy sites such as a sacral or pudendal nerve. Electrodes 20of the common lead 18 may deliver stimulation to the same or differentnerves. In other examples of therapy system 10, trial stimulator 16 maybe coupled to more than one lead that includes electrodes for deliveryof electrical stimulation to different stimulation sites within patient14, e.g., to target different nerves. In the example shown in FIG. 1,percutaneous lead 18 is cylindrical. Electrodes 20 may be cuffelectrodes, ring electrodes, segmented electrodes or partial ringelectrodes. In one example, lead 18 may include a paddle-shaped distalend on which one or more electrodes are arranged.

Trial stimulator 16 may include one or more sensors for detectingchanges in the contraction of bladder 12 as a mechanism for improvingthe efficacy of therapy delivered to patient 14. For example, trialstimulator 16 may include or be coupled to a pressure sensor fordetecting changes in bladder pressure, electrodes for sensing pudendalor sacral afferent nerve signals, or electrodes for sensing urinarysphincter EMG signals, or any combination thereof. In other examples,trial stimulator 16 may include a patient motion sensor that generates asignal indicative of patient activity level or posture state. In someexamples, trial stimulator 16 controls the delivery of stimulationtherapy to patient 14 based on sensed patient activity level or posturestate. For example, a patient activity level that is greater than orequal to a threshold may indicate that there is an increase in urgencyand/or an increase in the probability that an incontinence event willoccur, and accordingly, trial stimulator 16 may provide electricalstimulation based on the patient activity level. As an additionalexample, patient 14 may be more prone to urgency or an incontinenceevent when patient 14 is in an upright posture state compared to a lyingdown posture state. Accordingly, in some examples, trial stimulator 16may control the delivery of electrical stimulation to patient based onthe patient posture state determined based on a signal generated by amotion sensor.

System 10 includes an external programmer 24, as shown in FIG. 1. Insome examples, programmer 24 may be a wearable communication device,handheld computing device, computer workstation, or networked computingdevice. Programmer 24 may include a user interface that receives inputfrom a user (e.g., patient 14, a patient caretaker or a clinician). Theuser interface may include a keypad and a display (e.g., an LCDdisplay). The keypad may take the form of an alphanumeric keypad or areduced set of keys associated with particular functions of programmer24. Programmer 24 can additionally or alternatively include a peripheralpointing device, such as a mouse, via which a user may interact with theuser interface. In some examples, a display of programmer 24 may includea touch screen display, and a user may interact with programmer 24 viathe touch screen display. It should be noted that the user may alsointeract with programmer 24 and/or trial stimulator 16 remotely via anetworked computing device.

Patient 14 may interact with programmer 24 to control trial stimulator16 to deliver the stimulation therapy, to manually abort the delivery ofthe stimulation therapy by trial stimulator 16 while trial stimulator 16is delivering the therapy or is about to deliver the therapy, or toinhibit the delivery of the stimulation therapy by trial stimulator 16,e.g., during voluntary voiding events. Patient 14 may, for example, usea touch screen of programmer 24 to cause trial stimulator 16 to deliverthe stimulation therapy, such as when patient 14 senses that a leakingepisode may be imminent. In this way, patient 14 may use programmer 24to control the delivery of the stimulation therapy “on demand,” e.g.,when extra stimulation therapy is desirable.

Patient 14 may interact with programmer 24 to inhibit the delivery ofthe stimulation therapy during voluntary voiding events or to modify thetype of stimulation therapy that is delivered (e.g., to control trialstimulator 16 to deliver stimulation therapy to help patient 14voluntarily void in examples in which patient 14 has a urinary retentiondisorder). That is, patient 14 may use programmer 24 to enter input thatindicates the patient will be voiding voluntarily. When trial stimulator16 receives the input from programmer 24, trial stimulator 16 maysuspend delivery the stimulation therapy for a predetermined period oftime, e.g., two minutes, to allow the patient to voluntarily void, orswitch to a different type of stimulation therapy to help patient 14voluntarily void.

A user other than patient 14, such as a physician, technician, surgeon,electrophysiologist, or other clinician, may also interact withprogrammer 24 or another separate programmer (not shown), such as aclinician programmer to communicate with trial stimulator 16. Such auser may interact with a programmer to retrieve physiological ordiagnostic information from trial stimulator 16. The user may alsointeract with a programmer to program trial stimulator 16. e.g., selectvalues for the stimulation parameters according to which trialstimulator 16 generates and delivers electrical stimulation and/or otheroperational parameters of trial stimulator 16. For example, the user mayuse programmer 24 to retrieve information from trial stimulator 16regarding the contraction of bladder 12 and voiding events. As anotherexample, the user may use programmer 24 to retrieve information fromtrial stimulator 16 regarding the performance or integrity of trialstimulator 16 or other components of system 10, such as lead 18, or apower source of trial stimulator 16.

Trial stimulator 16 and programmer 24 communicate wirelessly. Examplesof wireless communication techniques employed by stimulator 16 andprogrammer 24 may include, for example, low frequency or radiofrequency(RF) telemetry, but other techniques are also contemplated.

Trial stimulator 16 may commonly be secured to the body of patient 14 ina position that makes manipulation of controls integral with thestimulator inconvenient or impractical. For example, trial stimulator 16may be secured to the back of patient 14 adjacent the waste line of thepatient. As such, the vast majority of interaction with and control oftrial stimulator 16 is executed by users via electronic programmer 24,which wireless communicates with the stimulator. Trial stimulator 16does include, however, a single user interface, button 30 integral withthe stimulator. Button 30 is conveniently located on one of the twolarger faces of trial stimulator 16, e.g. in the center of the face asillustrated in FIG. 1, to make the control easier for patient 14 tolocate. Additionally, button 30 may include structural features to makeit easier to locate, like a raised edge around the perimeter of thebutton or a surface finish or coating or texture that differs from theother surfaces of trial stimulator 16. Button 30 is employed for twoimportant functions that may not be best executed by programmer 24. Inparticular, button 30 is configured to cause trial stimulator 16 to becapable of wireless communication with programmer 24 and to turn offstimulation being delivered by the trial stimulator, e.g., in the eventthat patient 14 wishes to cease stimulation quickly without accessing afeature-rich user interface via programmer 24 or because programmer 24is unavailable. In other examples according to this disclosure, a trialstimulator may include a single user interface integral with thestimulator that is different than a button, e.g. a rocker switch, sliderswitch, or rotary dial switch.

FIGS. 2A-2C are conceptual diagrams of a number of views of exampletrial stimulator 16 of trial system 10 of FIG. 1. In FIGS. 2A-2C, trialstimulator 16 includes button 30 and is connected to lead extension 22via coupler 32. In one example, lead extension 22 may include a maleelectrical connector, or, plug that is configured to be received in afemale electrical connector, or, socket of coupler 32 of trialstimulator 16. In another example, lead extension 22 may include afemale electrical connector, or, socket that is configured to bereceived in a male electrical connector, or, plug of coupler 32 of trialstimulator 16. Trial stimulator 16 also includes battery bay 34, whichincludes cavity 36 and door 38. Battery bay 34 is configured to receiveone or more rechargeable or primary source batteries configured to powertrial stimulator 16. In one example, as illustrated in FIG. 2B, batterybay 34 is configured to receive a plurality of batteries, e.g., two AAAAdry cell alkaline batteries 40.

Trial stimulator 16 is configured to be disposed of after a single trialwith one patient, e.g. patient 14. As such, trial stimulator 16 may besterilized prior to use in a trial and may be arranged within a sterilefield during surgery and intraoperative testing of the stimulator.Because trial stimulator 16 is within the sterile field during surgery,the stimulator may encounter blood and other bodily fluids.Additionally, there may be instances in which trial stimulator 16 issubject to off-label uses by a patient, including showering or bathingwith the device. As such, in one example, trial stimulator 16 isconfigured to resist ingress of liquid into the device.

In some examples, trial stimulator 16 may not be hermetically sealed, asstructures and processes for achieving a hermetic seal may present toogreat a cost for a disposable device like disposable trial stimulator16. Trial stimulator 16 may, however, employ a number of techniques toresist ingress of liquid into the device. In one example, housing 42 oftrial stimulator 16 is configured to resist ingress of liquid into aninterior chamber defined by the housing. As illustrated in FIG. 2C,housing 42 may be include a first, or top half 42 a, and a second, orbottom half 42 b, which are joined at seam 44. Top half 42 a and bottomhalf 42 b may be joined at seam 44 by an ultrasonic weld that isconfigured to seal an interior chamber defined by housing 42 when topand bottom halves 42 a, 42 b are joined. Additionally, trial stimulator16 may include a seal that resists ingress of liquids into the device atthe interface between battery bay door 38 and bottom half 42 b ofhousing 42. For example, as illustrated in FIG. 2B. gasket 46 may beinterposed between battery bay door 38 and housing 42 to resist ingressof fluids into battery bay 34. Additionally, the junction between leadextension 22 and trial stimulator 16 via coupler 32 may be sealed withgasket 48, which, in one example, may take the form of an O-ring. Gasket48 between lead extension 22 and coupler 32 may be configured to resistingress of liquids into contact with the electrical connection betweenextension 22 and coupler 32.

Example disposable trial stimulator 16 of FIGS. 1 and 2A-2C may includea number of additional features. In one example, trial stimulator 16 maybe configured to automatically, and without user interaction, detect thetype of percutaneous stimulation lead 18 connected to the trialstimulator via lead extension 22. In one example, lead adaptor 26 mayinclude, in addition to electrical connections for connecting lead 18 tostimulator 16, an electrical contact that is configured to connect witha conductor of stimulation lead 18 in order to close a circuit that isconfigured to facilitate autonomous detection of the type of lead 18connected to stimulator 16. For example, adaptor 26 may include anelectrical contact that connects a conductor of stimulation lead 18 to acontrolled current source included in stimulator 16 that is configuredto deliver a particular amount of current across the lead conductor. Thecircuit with the controlled current source included in trial stimulator16 may be configured to measure the voltage drop across the leadconductor. Trial stimulator 16, e.g. a processor of trial stimulator 16may then calculate the resistance of the conductor of lead 18 based onthe delivered current and the measured voltage. In any event, Trialstimulator 16 may compare the actual resistance of the conductor ofstimulation lead 18 to a plurality of resistances associated with aplurality of lead types, e.g. stored in memory of trial stimulator 16and/or programmer 24.

In one example, trial stimulator 16 may not calculate resistance inorder to detect the type of lead connected thereto. Instead, the circuitwith the controlled current source included in trial stimulator 16 maybe configured to measure the voltage drop across the lead conductor andtrial stimulator 16 may compare the measured voltage drop across thelead conductor to stored voltage values associated with different leadtypes. Trial stimulator 16 may then determine the lead type based on thecomparison between measured voltage and stored voltage.

Autonomous lead detection may improve the efficiency and control ofprogramming stimulation therapy delivery for trial stimulator 16. Forexample, trial stimulator 16 may be configured to automatically limit atleast one of a number of stimulation programming options available viaprogrammer 24, limit or select one or more stimulation parameter values,or select different programs according to which the trial stimulator candeliver stimulation via stimulation lead 18 based on the type of thelead detected by the device.

In one example, trial stimulator 16 includes a diagnostics moduleconfigured to automatically cease delivery of stimulation whenstimulation lead 18 is disconnected from the trial stimulator, either bylead extension 22 being disconnected from coupler 22 or by lead 18 beingdisconnected from lead extension 22. Additionally, the diagnosticsmodule of trial stimulator 16 may be configured to monitor stimulationintensity delivered by trial stimulator 16 via lead 18 and generate analert when the stimulation intensity delivered by trial stimulator 16does not equal a programmed stimulation intensity, e.g. stored in memoryof stimulator 16 and/or programmer 24.

For example, stimulation lead 18 may include additional conductors thatfunction as resistors at the connection with trial stimulator 16 vialead extension 22. Trial stimulator 16 may then be configured to detectthe presence or absence of this resistor, e.g., by delivering currentacross the resistor from a power source of the stimulator. In the event,the resistance of the additional conductor is not detected, trialstimulator 16 may, e.g., automatically turn off stimulation and log anerror in memory of the device. Trial stimulator 16 may also generate avisual, audible, or tactile alert or communicate with programmer 24 tocause the programmer to generate an alert.

With regard to monitoring stimulation intensity, a stimulation engine oftrial stimulator 16 may be configured to measure the actual outputenergy of stimulation delivered by stimulator 16. In the event theactual stimulation output does not equal the programmed stimulation, anerror may be generated and logged and, in some examples, trialstimulator 16 may generate an alert. Depending on the nature of thestimulation error, e.g., the magnitude of the discrepancy betweenprogrammed stimulation intensity and actual output, a diagnostic moduleof trial stimulator 16 may prevent stimulation. In another example,trial stimulator 16 may detect is if the impedance in stimulation lead18 is either too low or too high and, e.g., trigger an alert asappropriate.

FIG. 3 is a schematic diagram illustrating another example trialstimulation system 100 including trial stimulator 102 coupled to a pairof percutaneous electrode arrays in the form of stimulation leads 106Aand 106B. Example trial stimulation system 100 including trialstimulator 102 is configured to be employed in a spinal cord stimulation(SCS) trial. The components of trial stimulation system 102 maygenerally include similar structures, functions, and variety of optionsdescribed above with reference to trial stimulation system 10 of FIG. 1.For example, the construction and general function of trial stimulator102 to deliver electrical stimulation via leads 106A and 106B to thespinal cord of patient 104 may be similar to that described above withreference to trial stimulator 16 and lead 18, including the constructionand optional types of leads employed, the materials from which thehousing of stimulator 102 is constructed, communications betweenprogrammer 108 and stimulator 102 and other general features andfunctions of trial stimulation system 100. Differences between system 10of FIG. 1 and system 100 will be apparent from the following descriptionof the components of and therapy delivered by trial stimulation system100.

As shown in FIG. 3, system 100 includes disposable trial stimulator 102,stimulation leads 106A and 106B, and external programmer 108, all ofwhich are shown in conjunction with patient 104. In the example of FIG.3, trial stimulator 102 is a disposable electrical stimulator configuredfor SCS, e.g., for relief of chronic pain or other symptoms. Stimulationleads 106A and 106B are connected to trial stimulator 102 and implantedthrough incision 110 and then tunneled through tissue of patient 104 toa therapy delivery site proximate spinal cord 112. Patient 104 isordinarily a human patient, but may also be a non-human patientincluding, e.g., a primate, canine, equine, pig, and feline.

Trial stimulator 102, in general, has an outer housing that isconstructed of a biocompatible material that resists corrosion anddegradation from bodily fluids including, e.g., a polymeric materialincluding silicone, polyurethane, or other biologically inert polymers.In one example, the housing of trial stimulator 102 is fabricated fromone or more thermoplastics. For example, the housing of stimulator 102may be fabricated from a polycarbonate and ABS polymer blend. In oneexample, the housing of trial stimulator 102 may be fabricated fromCycoloy® C2950HF PC+ABS from SABIC Innovative Plastics of Pittsfield,Mass. As described in more detail with reference to FIGS. 4A and 4B.trial stimulator 102 is a body-worn device that may, in one example, besecured to the back of patient 104. Trial stimulator 102 may be securedto patient 104 in a number of ways, including by, e.g. adhering asurface of the device to the skin of patient 104 with an adhesive ortaping the device to the patient with an adhesive tape. Additionally,FIGS. 8A-9C illustrate systems according to this disclosure for securingbody-worn trial stimulators, including, e.g. trial stimulator 102, tothe body of a patient.

Stimulation energy is delivered from trial stimulator 102 to spinal cord112 of patient 104 via one or more electrodes of implantable leads 106Aand 106B (collectively “leads 106”). The electrodes (not shown) may be,e.g., electrode pads on a paddle lead. circular (e.g., ring) electrodessurrounding the body of leads 106, conformable electrodes, cuffelectrodes, segmented electrodes, or any other type of electrodescapable of forming unipolar, bipolar or multipolar electrodeconfigurations for therapy. In some applications, such as SCS to treatchronic pain, the adjacent implantable leads 106 may have longitudinalaxes that are substantially parallel to one another.

The therapy parameters for a therapy program that controls delivery ofstimulation therapy by trial stimulator 102 through the electrodes ofleads 106 may include information identifying which electrodes have beenselected for delivery of stimulation according to a stimulation program,the polarities of the selected electrodes, i.e., the electrodeconfiguration for the program, and voltage or current amplitude, pulserate, and pulse width of stimulation delivered by the electrodes.Delivery of stimulation pulses will be described for purposes ofillustration. However, stimulation may be delivered in other forms suchas continuous waveforms.

In the example of FIG. 3, leads 106 carry electrodes that are placedadjacent to the target tissue of spinal cord 112. One or more of theelectrodes may be disposed at or near a distal tip of a lead 106 and/orat other positions at intermediate points along the lead. As notedabove, leads 106 may be implanted percutaneously, or surgically througha laminectomy or laminotomy through incision 110 and coupled to trialstimulator 102.

Trial stimulator 102 delivers electrical stimulation therapy to patient104 via selected combinations of electrodes carried by one or both ofleads 106. The target tissue for the electrical stimulation therapy maybe any tissue affected by electrical stimulation energy, which may be inthe form of electrical stimulation pulses or continuous waveforms. Insome examples, the target tissue includes nerves, smooth muscle orskeletal muscle. In the example illustrated by FIG. 3, the target tissueis tissue proximate spinal cord 112, such as within an intrathecal spaceor epidural space of spinal cord 112, or, in some examples, adjacentnerves that branch off of spinal cord 112. Leads 106 may be introducedinto spinal cord 112 via any suitable region, such as the thoracic,cervical or lumbar regions. Stimulation of spinal cord 112 may, forexample, prevent pain signals from traveling through spinal cord 112 andto the brain of patient 104. Patient 104 may perceive the interruptionof pain signals as a reduction in pain and, therefore, efficacioustherapy results.

In the example of FIG. 3, stimulation energy is delivered by trialstimulator 102, e.g. by a therapy delivery module of trial stimulator102 to the spinal cord 112 to reduce the amount of pain perceived bypatient 104. Although FIG. 3 is directed to SCS therapy, trialstimulation system 100 may alternatively be directed to any othercondition that may benefit from stimulation therapy. For example, system100 may be used to treat urinary urgency or incontinence via sacralstimulation, tremor, Parkinson's disease, epilepsy, sexual dysfunction,obesity, gastroparesis, or psychiatric disorders (e.g., depression,mania, obsessive compulsive disorder, anxiety disorders, and the like).In this manner, system 100 may be configured to provide therapy takingthe form of deep brain stimulation (DBS), peripheral nerve stimulation(PNS), peripheral nerve field stimulation (PNFS), cortical stimulation(CS), gastric stimulation, or any other stimulation therapy capable oftreating a condition of patient 104. The electrical stimulationdelivered by trial stimulator 102 may take the form of electricalstimulation pulses or continuous stimulation waveforms, and may becharacterized by controlled voltage levels or controlled current levels,as well as pulse width and pulse rate in the case of stimulation pulses.

As with trial stimulator 16 of system 10 of FIG. 1, disposable trialstimulator 102 may, in some examples, include one or more sensorsconfigured to monitor or detect a variety of parameters that may beemployed in the delivery of stimulation to patient 104, e.g. that may beemployed as a basis for improving the efficacy of therapy by modifyingstimulation parameters. For example, trial stimulator 102 may includeone or more posture sensors configured to detect the posture stateand/or activity level of patient 104. During use of trial stimulator 102to treat patient 104, movement of patient 104 among different posturestates may affect the ability of trial stimulator 102 to deliverconsistent efficacious therapy. For example, leads 106 may migratetoward trial stimulator 102 when patient 104 bends over, resulting indisplacement of electrodes and possible disruption in delivery ofeffective therapy. Stimulation energy transferred to target tissue maybe reduced due to electrode migration, causing reduced efficacy in termsof relief of symptoms such as pain. In such a case, trial stimulator 102may be configured to automatically modify stimulation parameters basedsensor signals indicating patient 104 is bending over. As anotherexample, leads 106 may be compressed towards spinal cord 112 whenpatient 104 lies down. Such compression may cause an increase in theamount of stimulation energy transferred to target tissue. In this case,the amplitude of stimulation therapy may need to be decreased to avoidcausing patient 104 additional pain or unusual sensations, which may beconsidered undesirable side effects that undermine overall efficacy.

System 100 includes an external programmer 108, as shown in FIG. 3. Insome examples, programmer 108 may be a wearable communication device,handheld computing device, computer workstation, or networked computingdevice. Programmer 108 may include a user interface that receives inputfrom a user (e.g., patient 104, a patient caretaker or a clinician). Theuser interface may include a keypad and a display (e.g., an LCDdisplay). The keypad may take the form of an alphanumeric keypad or areduced set of keys associated with particular functions of programmer108. Programmer 108 can additionally or alternatively include aperipheral pointing device, such as a mouse, via which a user mayinteract with the user interface. In some examples, a display ofprogrammer 108 may include a touch screen display, and a user mayinteract with programmer 108 via the touch screen display. It should benoted that the user may also interact with programmer 108 and/or trialstimulator 102 remotely via a networked computing device.

Programmer 108 may function and be used by different users, e.g. patient104 and a clinician, in a manner similar to that described above withreference to programmer 24 of trial stimulation system 10. Trialstimulator 102 and programmer 108 communicate wirelessly. Examples ofwireless communication techniques employed by stimulator 102 andprogrammer 108 may include, for example, low frequency or radiofrequency(RF) telemetry, but other techniques are also contemplated.

As described above, some current trial stimulation systems commonlyemploy leads, which are connected to a lead extension and/or adaptorconnected to a trial stimulator that is worn externally on the clothingor a lanyard. Externalization of the trial stimulator, as well as thenecessity for the lead extension and/or adaptor may increase thelikelihood of inaccurate tests results because system wires can becomehung up on clothing or the environment (door knob) or otherwiseinterfered with, potentially causing dislocation of the stimulatingelectrodes within the body of the patient. Additionally, the use ofadditional components such as bulky lead extensions and/or adaptors maybe costly and inconvenient for patients. Additionally, lead extensionsintroduce another possible point of failure or malfunction in theconnection between lead and stimulator. In view of the foregoingdisadvantages of the use of lead extensions and/or adaptors in trialstimulation systems, disposable trial stimulator 102 includes a leadcoupler integral with stimulator 102 that connects leads 106 directly to102 without any intervening lead connection devices.

FIGS. 4A and 4B are conceptual diagrams of a number of views of exampledisposable trial stimulator 102 of system 100 of FIG. 3. In FIGS. 4A and4B, trial stimulator 102 includes housing 120, lead coupler 122, andbutton 124. Trial stimulator 102 is connected to lead 106 including fourelectrodes 126A-126D (collectively “electrodes 126”) via lead coupler122. Housing 120 includes a first, or top half 120 a, and a second, orbottom half 120 b. Top half 120 a of housing 120 includes two leadcoupler doors 128 and 130, which are configured to pivot open to exposelead coupler 122. The junction between housing 120 and doors 128 and 130also includes apertures 132A-132D, which are configured to accommodate,in the example of FIGS. 4A and 4B, up to four percutaneous leadsconnected to trial stimulator 102 via lead coupler 122.

As noted above and as illustrated in FIG. 4B, lead coupler doors 128 and130 pivot open to expose lead coupler 122, which in the example of trialstimulator 102 is configured to connect up to four stimulation leads tothe disposable stimulator. In other examples, trial stimulator 102 oranother disposable trial stimulator according to this disclosure mayinclude a lead coupler configured to accommodate more or fewerstimulation leads than example coupler 122. Opening doors 128 and 130exposes six slots 134A-134D (collectively “slots 134”) included in leadcoupler 122. In one example, slots 134 include 2 slots, 134A and 134Fwith 8 contacts, each of which is configured to receive one lead witheight electrodes. Additionally, slots 134 may include slots 134B-134Ewith four contacts, each of which is configured to receive one lead withfour electrodes, like lead 106 including electrodes 126. Each of slots134 of lead coupler 122 of trial stimulator 102 is configured to connectone stimulation lead to stimulator 102. For example, percutaneousstimulation lead 106 is connected directly to trial stimulator withoutany intervening lead connection devices via slot 134D of lead coupler122. Each of slots 134 may include one or more electrical contacts, likecontact 136 illustrated with reference to slot 134D in FIG. 4A.Stimulation leads, like lead 106 may be press fit into slots 134 and maybe configured with exposed electrical conductors arranged along the endof the lead received by the slots, e.g. the proximal end of the lead,such that the lead conductors contact the electrical contacts in slots134. Stimulation leads, like lead 106 may thus be electrically connectedto trial stimulator 102 such that stimulator 102 may deliver stimulationtherapy to a patient via electrodes arranged at the distal end of thelead, e.g. electrodes 126A-126D and connected to the lead conductorscontacting the electrical contacts of slots 134.

In some examples, additional electrical connections between astimulation lead and lead coupler 122 of trial stimulator 102 may beprovided for reasons other than connecting stimulation electrodes to atherapy delivery module of stimulator 102. In one example, each of slots134 of lead coupler 122 may include an electrical contact that isconfigured to connect with a conductor of a stimulation lead in order toclose a circuit that is configured to facilitate autonomous detection ofthe type of lead connected to stimulator 102. For example, each of slots134 of lead coupler 122 may include an electrical contact that connectsa conductor of a stimulation lead to a controlled current source that isconfigured to deliver a particular amount of current across the leadconductor. The circuit with the controlled current source included intrial stimulator 102 may be configured to measure the voltage dropacross the lead conductor. Trial stimulator 102, e.g. a processor oftrial stimulator may then calculate the resistance of the conductor ofthe lead based on the delivered current and the voltage. Trialstimulator 102 may compare the actual resistance of the conductor of thestimulation lead to a plurality of resistances associated with aplurality of lead types, e.g. stored in memory of trial stimulator 102and/or programmer 108.

In one example, trial stimulator 102 may not calculate resistance inorder to detect the type of lead connected thereto. Instead, the circuitwith the controlled current source included in trial stimulator 102 maybe configured to measure the voltage drop across the lead conductor andtrial stimulator 102 may compare the measured voltage drop across thelead conductor to stored voltage values associated with different leadtypes. Trial stimulator 102 may then determine the lead type based onthe comparison between measured voltage and stored voltage.

Autonomous lead detection may improve the efficiency and control ofprogramming stimulation therapy delivery for trial stimulator 102. Forexample, trial stimulator 102 may be configured to automatically limit anumber of stimulation programming options available via programmer 108,limit or select one or more stimulation parameter values, or selectdifferent programs according to which the trial stimulator can deliverstimulation via stimulation lead 106 based on the type of the leaddetected by the device.

As with trial stimulator 16 of FIG. 1, trial stimulator 102 may commonlybe secured to the body of patient 104 in a position that makesmanipulation of controls integral with the stimulator inconvenient orimpractical. For example, trial stimulator 102 may be secured to theback of patient 104 adjacent the waste line of the patient. As such, thevast majority of interaction with and control of trial stimulator 102 isexecuted by users via electronic programmer 108, which wirelesscommunicates with the stimulator. Trial stimulator 102 does include,however, a single user interface, button 124 integral with thestimulator. Button 124 is conveniently located on one of the two largerfaces of trial stimulator 102, e.g. in the center of top half 120 a ofhousing 120 as illustrated in FIG. 4A. to make the control easier forpatient 104 to locate. Additionally, button 124 may include structuralfeatures to make it easier to locate, like a raised edge around theperimeter of the button or a surface finish or coating or texture thatdiffers from the other surfaces of trial stimulator 102. Button 124 isemployed for two important functions that may not be best executed byprogrammer 108. In particular, button 124 is configured to cause trialstimulator 102 to be capable of wireless communication with programmer108 and to turn off stimulation being delivered by the trial stimulator,e.g., in the event that patient 104 wishes to cease stimulation quicklywithout accessing a feature-rich user interface via programmer 108 orbecause programmer 108 is unavailable.

Trial stimulator 102 is configured to be disposed of, i.e., discardedafter a single trial with one patient, e.g. patient 104. As such, trialstimulator 102 may be sterilized prior to use in a trial and may bearranged within a sterile field during surgery and intraoperativetesting of the stimulator. Because trial stimulator 102 is within thesterile field during surgery, the stimulator may encounter blood andother bodily fluids. Additionally, there may be instances in which trialstimulator 102 is subject to off-label uses by a patient, includingshowering or bathing with the device. As such, in one example, trialstimulator 102 is configured to resist ingress of liquid into thedevice.

In some examples, trial stimulator 102 may not be hermetically sealed,as achieving a hermetic seal may be too great a cost for a disposabledevice like disposable trial stimulator 102. Trial stimulator 102 may,however, employ a number of techniques to resist ingress of liquid intothe device. In one example, housing 120 of trial stimulator 102 isconfigured to resist ingress of liquid into an interior chamber definedby the housing. For example, housing 120 may include a number ofsections that are connected to one another to define one or more closedchambers in which various components of trial stimulator 102 arearranged. In one example, different sections of housing 120 areconnected by ultrasonic welds that are configured to resist ingress ofliquids into the interior chamber(s) of trial stimulator 102. Housing120 of stimulator 102 includes top half 120 a and bottom half 120 b. Tophalf 120 a of housing 120 includes lead coupler doors 128 and 130. Inone example, the junction between top half 120 a including doors 128 and130 and bottom half 120 b of housing 120 may include a gasket that isconfigured to seal lead coupler 122 inside doors 128 and 130 in order toresist ingress of liquids into the lead coupler.

Trial stimulator 102 may include a battery bay including a cavity anddoor as described above with reference to stimulator 16 of system 10. Insuch cases, the interface between the battery bay door and housing 120of trial stimulator 102 may be sealed with a gasket that is configuredto resist ingress of liquids into the cavity of the battery bay.

Example disposable trial stimulator 102 of FIGS. 3 and 4A and 4B mayinclude a number of additional features. In one example, trialstimulator 102 includes a diagnostics module configured to automaticallycease delivery of stimulation when stimulation leads 106 aredisconnected from the trial stimulator. Additionally, the diagnosticmodule may be configured to monitor stimulation intensity delivered bytrial stimulator 102 via leads 106 and generate an alert when thestimulation intensity delivered by trial stimulator 102 does not equal aprogrammed stimulation intensity, e.g. stored in memory of stimulator102 and/or programmer 108.

For example, stimulation leads 106 may include additional conductorsthat function as resistors at the connection with trial stimulator 102via lead coupler 122. The diagnostics module of trial stimulator 102 maythen be configured to detect the presence or absence of this resistor,e.g., by delivering current across the resistor from a power source ofthe stimulator. In the event, the resistance of the additional conductoris not detected, the diagnostic module of trial stimulator 102 may,e.g., automatically turn off stimulation and log an error in memory ofthe device. Trial stimulator 102 may also generate a visual, audible, ortactile alert or communicate with programmer 108 to cause the programmerto generate an alert.

With regard to monitoring stimulation intensity, a stimulation engine oftrial stimulator 102 may be configured to measure the actual outputenergy of stimulation delivered by stimulator 102. In the event theactual stimulation output does not equal the programmed stimulation, anerror may be generated and logged and, in some examples, trialstimulator 16 may generate an alert. Depending on the nature of thestimulation error, e.g., the magnitude of the discrepancy betweenprogrammed stimulation intensity and actual output or in the eventstimulation intensity is detected that is outside of a hard limit set byphysician programming, a diagnostic module of trial stimulator 102 mayprevent stimulation. In another example, trial stimulator 102 may detectis if the impedance in stimulation leads 106 is either too low or toohigh and, e.g., trigger an alert as appropriate.

In one example, a diagnostic module of trial stimulator 102 is alsoconfigured to detect whether doors 128 or 130 are open, e.g. via acircuit including a switch that is normally closed or open in the dooropen or closed state. In the event the diagnostic module of trialstimulator 102 detects that either door 128 or 130 is open, in oneexample, trial stimulator 102 may be configured to turn off stimulationbeing delivered at the time.

FIG. 5 is a functional block diagram illustrating example components ofan example disposable trial stimulator 200 according to this disclosure.The configuration and componentry of trial stimulator 200 may beimplemented in a number of different types of trial stimulation systems,including, e.g., trial stimulator 16 of system 10 of FIG. 1 and trialstimulator 102 of system 100 of FIG. 3. However, there may be functionaland structural differences depending on which type of system trialstimulator 200 of FIG. 5 is implemented in. For example, the sensorsincluded in trial stimulator 200 may differ if the device is included ina trial stimulation system configured to deliver pelvic floorstimulation, like system 10 of FIG. 1, versus if the device is includedin a trial stimulation system configured to deliver SCS therapy, likesystem 100 of FIG. 3. Moreover, trial stimulator 200 may includeadditional components if the device is included in a trial stimulationsystem configured to deliver pelvic floor stimulation, like system 10 ofFIG. 1, e.g. an impedance module for monitoring bladder impedance todetect bladder contractions, versus if the device is included in a trialstimulation system configured to deliver SCS therapy, like system 100 ofFIG. 3.

In the example of FIG. 5, trial stimulator 200 includes sensor (2) 202,processor 204, memory 206, therapy delivery module 208, telemetry module210, user interface 212, power management module 214, diagnostic module220, and power source 222. Processor 204 may be programmed to control anumber of components of trial stimulator 200 including therapy deliverymodule 208 and telemetry module 210, e.g., based on instructions anddata stored in memory 206, as well as sensor data from sensor(s) 202.Therapy delivery module 208 is connected to lead 216 includingelectrodes 218A-218D (collectively “electrodes 218”) and is configuredto deliver electrical stimulation therapy through electrodes 218 to oneor more target tissue sites within a patient. As illustrated in theexample of FIG. 5, power management module 214 may be connected toprocessor 204, telemetry module 210, and user interface 212.

Processor 204 is operably connected to and configured to accessinformation from memory 206 and to control therapy delivery module 208.Components described as processors within trial stimulator 200, or anyother device described in this disclosure may each comprise one or moreprocessors, such as one or more microprocessors, digital signalprocessors (DSPs), application specific integrated circuits (ASICs),field programmable gate arrays (FPGAs), programmable logic circuitry, orthe like, either alone or in any suitable combination. The functionsattributed to trial stimulator 200 may be embodied in a hardware devicevia software, firmware, hardware or any combination thereof.

Memory 206 may store instructions for execution by processor 204,stimulation therapy data, sensor data, e.g. bladder impedancemeasurements and/or posture state data, and any other informationregarding therapy of a patient employing trial stimulator 200. Therapyinformation may be recorded for long-term storage and retrieval by auser, and the therapy information may include any data created by orstored in trial stimulator 200. Memory 206 may include separate memoriesfor storing instructions, sensor data, therapy adjustment information,program histories, and any other data that may benefit from separatephysical memory modules. Memory 206 may include any volatile ornon-volatile media, such as a random access memory (RAM), read onlymemory (ROM), non-volatile RAM (NVRAM), electrically erasableprogrammable ROM (EEPROM), flash memory, and the like.

Processor 204 controls therapy delivery module 208 to deliver electricalstimulation via electrode combinations formed by electrodes in one ormore electrode arrays. For example, therapy delivery module 208 maydeliver electrical stimulation therapy via electrodes 218 on lead 216,e.g., as stimulation pulses or continuous waveforms. Therapy deliverymodule 208 may include stimulation generation circuitry to generatestimulation pulses or waveforms and switching circuitry to switch thestimulation across different electrode combinations, e.g., in responseto control signals from processor 204. In particular, processor 204 maycontrol the switching circuitry on a selective basis to cause therapydelivery module 208 to deliver electrical stimulation to selectedelectrode combinations and to shift the electrical stimulation todifferent electrode combinations in a various directions when thetherapy is delivered to different locations within a patient.

Therapy delivery module 208 of example disposable trial stimulator 200may be configured to deliver current or voltage controlled stimulationvia various electrodes of one or more electrode arrays, including, e.g.different combinations of electrodes 218 on lead 216. In one example,therapy delivery module 208 may include multiple current sources todrive more than one electrode combination at one time.

In one example in which therapy delivery module 208 is configured todeliver current controlled stimulation and includes multiple currentsources, therapy delivery module 208 includes a stimulation generatorincluding a voltage supply, a stimulation control module, and a currentregulator array. The voltage supply of therapy delivery module 208 mayreceive operating power from power source 222. In turn, the voltagesupply of therapy delivery module 208 may provide a supply voltage tocurrent regulators in the current regulator array. The voltage supplymay provide a high supply voltage (V_(HIGH)) and a low supply voltage(V_(LOW)). The high supply voltage may be coupled to a regulated currentsource as a supply voltage. The low supply voltage may be coupled to aregulated current sink as a supply voltage. The supply voltage level maybe the voltage level used by the current regulator to maintainregulation of the pulse current level. The high and low supply voltagesmay be positive and negative voltages, respectively, supplied by thevoltage supply of therapy delivery module. The high supply voltageV_(HIGH) may be used as a high reference voltage level for a currentsource, and the low supply voltage V_(LOW) may be used as a lowreference voltage level for a current sink. As an example, V_(HIGH) mayhave a voltage level of approximately +1 V to +10 V, and V_(LOW) mayhave a voltage level of approximately −1 V to −10 V.

In one example, therapy delivery module 208 includes a stimulationcontrol module that is configured to control the current regulator arrayto source and sink regulated current stimulation pulses via selectedcombinations of electrodes 218 on lead 216. The stimulation controlmodule may be implemented in hardware, software, or combinationsthereof, including, e.g., one or more microprocessors, microcontrollers,digital signal processors (DSPs), application-specific integratedcircuits (ASICs), field-programmable gate arrays (FPGAs), or otherintegrated or discrete logic circuitry. In operation, the stimulationcontrol module of therapy delivery module 208 may control delivery ofelectrical stimulation according to one or more programs that specifystimulation parameters such as electrode combination, electrodepolarity, stimulation current pulse amplitude, pulse rate, and/or pulsewidth. Programs may be defined by a user via an external programmer anddownloaded to trial stimulator 200 for use by the stimulation controlmodule of therapy delivery module 208.

In one example, the current regulator array of therapy delivery module208 may include a plurality of regulated current sources and sinks, eachof which may be coupled to a respective electrode, e.g. a respective oneof electrodes 218. A current regulator may function as either a currentsource or sink, e.g., by including a source and sink in parallel or byotherwise being selectively configurable to operate as either a sourceor a sink. For convenience, however, the term “current regulator” may beused in this disclosure to refer generally to either a source or sink.Hence, each of the current regulators in the current regulator array oftherapy delivery module 208 may operate as a regulated current sourcethat delivers stimulation via a corresponding one of electrodes218A-218D or a regulated current sink that receives current from acorresponding one of electrodes 218A-218D.

Each current regulator of the current regulator array of therapydelivery module 208, in one example, may be selectively activated tosource or sink current via one of electrodes 218 coupled to theregulator, in which case the electrode is considered active, ordeactivated to provide a high impedance connection for the electrode, inwhich case the electrode may be considered inactive. Hence, eachelectrode 218 may function as a regulated anode or regulated cathode byconnection to a regulated current source or regulated current sink, orfunction as a high impedance node that may not source or sink asignificant amount of current. In some examples, the stimulation controlmodule of therapy delivery module 208 may selectively activate currentregulators in the current regulator array to configure electrodes 218 inunipolar, bipolar or multipolar electrode configurations.

In some examples, pulse widths and pulse rates may be selectivelycontrolled by the stimulation control module of therapy delivery module208 by selectively activating current regulators in the currentregulator array, e.g., on a pulse-by-pulse basis, at selected times andfor selected durations. The current regulator array of therapy deliverymodule, in some examples, may also control the shape of the pulses tocontrol the rise time, overshoot, or overall shape (triangle versussquare). In addition, the stimulation control module of therapy deliverymodule 208 may selectively control individual regulated current sourcesor sinks in the current regulator array to deliver stimulation currentpulses via the selected electrodes with desired current levels.

In some examples, therapy delivery module 208 is configured to simulatevoltage controlled stimulation with a current controlled stimulationengine. For example, therapy delivery module 208 may be configured tovary the current level of the stimulation delivered based on changingimpedance levels in the target tissue being stimulated in order todeliver stimulation at a substantially constant voltage amplitude. Inone example, therapy delivery module 208 may include voltage measurementcircuitry and a current source that are employed to measure tissueimpedance levels, which may be employed to vary current to simulatevoltage controlled stimulation. Therapy delivery module 208 may alsoinclude an oscillator (not shown) or the like for producing analternating signal, as is known. In one example, therapy delivery module208 may periodically control the current source to source an electricalcurrent signal through an electrode, on of electrodes 218 not being usedfor stimulation delivery and sink the electrical current signal throughanother o electrodes 218 not being used for stimulation delivery.Therapy delivery module 208 may also include voltage measurementcircuitry 62 for measuring the voltage between the source and sinkelectrodes. The voltage measurement circuitry may, e.g., include sampleand hold circuitry or other suitable circuitry for measuring voltageamplitudes. Therapy delivery module may determine an impedance valuefrom the measured voltage values received from the voltage measurementcircuitry and may adjust the current controlled stimulation levels basedon the impedance to simulate stimulation delivered at a substantiallyconstant voltage amplitude. Therapy may delivered in this mode and otherstimulation modes via unipolar, bipolar, or multipolar electrodecombinations.

An exemplary range of electrical stimulation parameters that may beeffective in treating chronic pain, e.g., when applied to a spinal cordof a patient by therapy delivery module 208 of trial stimulator 200, arelisted below. While stimulation pulses are described, stimulationsignals may be of any of a variety of forms such as sine waves or thelike. Stimulation parameters are presented below for purpose of example,but without limitation.

Pulse Rate: between approximately 0.5 Hz and approximately 1200 Hz, morepreferably between approximately 5 Hz and approximately 250 Hz, andstill more preferably between approximately 30 Hz and approximately 130Hz.

Amplitude: between approximately 0.1 milliamps (mA) and approximately 50mA. In other examples, a voltage amplitude may define the intensity ofstimulation delivered to a patient. For example, the range of voltageamplitude may be between approximately 0.1 volts and approximately 50volts, more preferably between approximately 0.5 volts and approximately20 volts, and still more preferably between approximately 1 volt andapproximately 10 volts.

Pulse Width: between approximately 10 microseconds and approximately5000 microseconds, more preferably between approximately 100microseconds and approximately 1000 microseconds, and still morepreferably between approximately 180 microseconds and approximately 450microseconds.

In other applications, different ranges of parameter values may be used.For DBS, as one example, alleviation or reduction of symptoms associatedwith Parkinson's disease, essential tremor, epilepsy, psychiatricdisorders or other disorders may make use of stimulation having a pulserate in the range of approximately 0.5 Hz to approximately 1200 Hz. suchas approximately 5 Hz to approximately 250 Hz, or approximately 30 Hz toapproximately 185 Hz, and a pulse width in the range of approximately 10microseconds and 5000 microseconds, such as between approximately 60microseconds and approximately 1000 microseconds, between approximately60 microseconds and approximately 450 microseconds, or betweenapproximately 60 microseconds and approximately 150 microseconds.Amplitude ranges such as those described above with reference to SCS, orother amplitude ranges, may be used for different DBS applications.Additionally, different stimulation parameter values may be employed forother conditions, including, e.g., to treat various pelvic floordisorders including urgency and urinary incontinence.

Telemetry module 210 may enable wireless telemetry between trialstimulator 200 and one or more other electronic devices, including,e.g., an electronic programming device. Telemetry module 210 may enablewireless communications, including, via radio frequency (RF)communication or proximal inductive interaction of trial stimulator 200with another electronic device. Telemetry module 210 may sendinformation to and receive information from another device on acontinuous basis, at periodic intervals, at non-periodic intervals, orupon request from trial stimulator 200 or an electronic programmer. Tosupport RF communication, telemetry module 210 may include appropriateelectronic components, such as amplifiers, filters, mixers, encoders,decoders, and the like. Additionally, telemetry module 210 may beconfigured to communicate via various wireless communication standardsand/or protocols, including, e.g., the Bluetooth wireless communicationstandard.

Example disposable trial stimulator 200 includes user interface 212 forfacilitating user interaction with the stimulator. As explained above,one disadvantage of current trial stimulation systems is the manner inwhich users interact with the system to control stimulation therapy orotherwise interact with the trial stimulator. In some current systems,the trial stimulator includes a number of user input/output controlsthat are necessary for operation of the system. However, as the trialstimulator in some such systems is commonly held or secured to the backof the patient, it is inconvenient or impractical for the patient tointeract with the I/O devices integral with the stimulator. Theinclusion of I/O devices integral with the trial stimulator alsoprevents maintaining the sterile field during surgery, as it may benecessary to interact with such devices during intraoperative testing ofthe stimulator. Additionally, some current trial stimulation systemsutilize programming devices for modulating the therapy, which, whileseparate from the trial stimulator, must nevertheless be directly nextto or very near the stimulator to communicate with it. Again, due to theplacement of the trial stimulator on or near the back of the patient,such programming devices are inconvenient or impractical to use.

In view of the foregoing challenges with current trial stimulationsystems, in one example, trial stimulator 200 includes a single userinterface 212, including, e.g., a button like button 30 of trialstimulator 16 of FIG. 1 or button 124 of trial stimulator 102 of FIG. 3.In such cases, user interface 212 may be configured to cause trialstimulator 200 to be capable of wireless communications with anelectronic programming device and to turn off stimulation beingdelivered by the trial stimulator. In one example, depending on theoperational state of trial stimulator 200 a single input to userinterface 212 will either cause trial stimulator 200 to be capable ofwireless communications with an electronic programming device or willcause the trial stimulator to stop delivering stimulation to thepatient. For example, in the event trial stimulator 200 is powered offor is in a lower power operating mode and is not currently deliveringstimulation, input to user interface 212 may cause trial stimulator 200to be capable of communications with an external programmer device. Inone example, input to user interface 212 may cause processor 204 tocontrol telemetry module 210 to transmit signals requestingcommunication with a communication system with any properly configuredprogramming devices, or with a particular device, within range of thesignals transmitted by telemetry module 210. In another example, inputto user interface 212 may cause processor 204 to control telemetrymodule 210 to listen for signals requesting communications from anelectronic programming device within range of trial stimulator 200. Inone example, input to user interface 212 may directly affect operationof telemetry module 210 to facilitate communication with a programmingdevice without going through processor 204.

In the event that therapy delivery module 208 of trial stimulator 200 iscurrently delivering stimulation, input to user interface 212 may causeprocessor 204 to stop delivering stimulation. For example, input to userinterface 212 while therapy delivery module 208 of trial stimulator 200is delivering stimulation may cause processor 204 to control therapydelivery module 208 to cease delivering stimulation but may notcompletely power off trial stimulator 200. In another example, input touser interface 212 may cause processor 204 to completely power off trialstimulator 200.

Trial stimulator 200 also includes power management module 214, which isconnected to processor 204, telemetry module 210, and user interface212. Power management module 214 may be configured to control trialstimulator 200 to operate in a plurality of power consumption modes. Inone example, power management module 214 is configured to control trialstimulator 200 to operate in a shelf low-power consumption mode and anoperational full-power mode. In one example, power management module 214may be configured to transition trial stimulator 200 from the shelflow-power consumption mode to the operational full-power mode duringinitial intraoperative set-up and programming of the trial stimulator.

In one example, trial stimulator 200 is shipped in the shelf low-powerconsumption mode, in which all of the components of trial stimulator 200except power management module 214 are not receiving power from powersource 222. Power management module 214 may be directly connected touser interface 212 of trial stimulator 200. In one example, when a useris ready to put trial stimulator 200 into a full-power consumption mode,the user may interact with user interface 212, which may, in turn,transmit a signal to power management module 214. Power managementmodule 214 may then function to cause power source 222 to deliver powerto one or more of the components of trial stimulator 200, including,e.g. sensors 202, processor 204, memory 206, therapy delivery module208, telemetry module 210, and diagnostic module 220.

In another example, trial stimulator 200 is shipped in the shelflow-power consumption mode, in which all of the components of trialstimulator 200 except power management module 214 and telemetry module210 are not receiving power from power source 222. In such an example,either a signal from an external device, e.g. an electronic programmingdevice to telemetry module 210 or input to user interface 212 may causepower management module 214 to cause power source 222 to deliver powerto one or more of the other components of trial stimulator 200,including, e.g. sensors 202, processor 204, memory 206, therapy deliverymodule 208, and diagnostic module 220. For example, input to userinterface 212 may cause power management module 214 to transition trialstimulator 200 to a full power mode in which all components, including,e.g., sensors 202, processor 204, memory 206, therapy delivery module208, and diagnostic module 220 receive power from power source 222. Inanother example, a near field telemetry signal, e.g., from an electronicprogramming device to telemetry module 214 may to “Wake Up” trialstimulator 200 such that power management module 214 transitionsstimulator 200 to a full power mode in which all components, including,e.g., sensors 202, processor 204, memory 206, therapy delivery module208, and diagnostic module 220 receive power from power source 222.

Trial stimulator 200 also includes diagnostic module 220. Diagnosticmodule 220 may be configured to perform a number of diagnostic functionsautonomously. For example, diagnostic module 220 may be configured tomonitor stimulation intensity delivered by therapy delivery module 208of trial stimulator 200 via electrodes 218 on lead 216 and generate analert when the stimulation intensity delivered by therapy deliverymodule 208 does not equal a programmed stimulation intensity, e.g.stored in memory 206 of stimulator 200 and/or memory of an electronicprogrammer in communication with stimulator 200.

In one example, diagnostic module 220 may also be configured toautomatically cease delivery of stimulation when stimulation lead 216 isdisconnected from trial stimulator 200 and detect the type of lead 216connected to stimulator 200. In some examples, electrical connectionsbetween stimulation lead 216 and trial stimulator 200 may be providedfor reasons other than connecting stimulation electrodes 218 to therapydelivery module 208 of stimulator 102. In one example, the connectionbetween lead 216 and trial stimulator 200 may include an electricalcontact that is configured to connect with a conductor of stimulationlead 216 in order to close a circuit, e.g., included in diagnosticmodule 220 that is configured to facilitate autonomous detection of thetype of lead connected to stimulator 200. For example, an electricalcontact may connects a conductor of stimulation lead 216 to a controlledcurrent source of therapy delivery module 208 that is configured todeliver a particular amount of current across the lead conductor. Thelead detection circuit of diagnostic module 220 with the controlledcurrent source included in therapy delivery module 208 may be configuredto measure the voltage drop across the lead conductor. Diagnostic module220 may then calculate the resistance of the conductor of lead 216 basedon the delivered current and the voltage. Diagnostic module 220 maycompare the actual resistance of the conductor of the stimulation leadto a plurality of resistances associated with a plurality of lead types,e.g. stored in memory 206 of trial stimulator 200 and/or memory of anelectronic programmer in communication with stimulator 200.

Autonomous lead detection may improve the efficiency and control ofprogramming stimulation therapy delivery for trial stimulator 200. Forexample, diagnostic module 220 or processor 204 of trial stimulator 200may be configured to automatically limit at least one of a number ofstimulation programming options available for programming via anelectronic programmer and one or more stimulation parameter valuesaccording to which therapy delivery module 208 of trial stimulator 200can deliver stimulation via stimulation lead 216 based on the type ofthe lead detected by the device.

Power source 222 delivers operating power to the components of trialstimulator 200. Power source 222 may include a battery and a powergeneration circuit to produce the operating power. In some examples, thebattery may be rechargeable to allow extended operation. Recharging maybe accomplished through proximal inductive interaction between anexternal charger and an inductive charging coil within trial stimulator200. In other examples, power source 222 may include one or more primarysource batteries, including, e.g. one or more commercially availablebatteries like AAAA dry cell alkaline batteries.

FIG. 6 is a functional block diagram illustrating example components ofelectronic programmer 300. While programmer 300 may generally bedescribed as a hand-held computing device, the programmer may be anotebook computer, a cell phone, or a workstation, for example, or anyother electronic device configured for wireless communications with atrial stimulator in accordance with this disclosure. As illustrated inFIG. 6, external programmer 300 may include a processor 302, memory 304,user interface 306, telemetry module 308, and power source 310. Memory304 may store program instructions that, when executed by processor 302,cause processor 302 to provide the functionality ascribed to programmer300 throughout this disclosure.

In some examples, memory 304 may further include programs, programgroups, and stimulation parameters defining stimulation therapy that maybe delivered by a trial stimulator, similar to those stored in memory206 of trial stimulator 200. The therapy programs or other instructionsstored in memory 304 may be downloaded into memory 206 of trialstimulator 200 via telemetry modules 210 and 308. Memory 304 may includeany volatile, non-volatile, fixed, removable, magnetic, optical, orelectrical media, such as RAM, ROM, CD-ROM, hard disk, removablemagnetic disk, memory cards or sticks, NVRAM, EEPROM, flash memory, andthe like.

Processor 302 can take the form of one or more processors such as one ormore microprocessors, DSPs, ASICs, FPGAs, programmable logic circuitry,or the like, and the functions attributed to processor 302 herein may beembodied as hardware, firmware, software or any combination thereof.Processor 302 may control or otherwise interact with components ofprogrammer 300, including, e.g., memory 304, user interface 306, andtelemetry module 308, to perform various functions related toprogramming a disposable trial stimulator according to this disclosure.For example, processor 302 may receive input from a user like aclinician via user interface 306 that defines one or more therapyparameters and/or programs, which processor then stores in memory 304and, in some cases, controls telemetry module 308 to transmit to a trialstimulator like stimulator 200 of FIG. 5.

User interface 306 may include a button or keypad, lights, a speaker forvoice commands, and a display, such as a liquid crystal (LCD). In someexamples, such as with example programmers 24 and 108 of FIGS. 1 and 3,respectively, user interface 306 may include a touch screen display. Asdiscussed in this disclosure, processor 302 may present and receiveinformation relating to stimulation therapy delivered by a trialstimulator via user interface 306. For example, processor 302 mayreceive patient input via user interface 306. The patient input may beentered, for example, by pressing a button on a keypad or selecting anicon from a touch screen. For the example of pelvic floor stimulation,patient input may include, but is not limited to, input that indicatesan urge felt by the patient, a leakage incident experienced by thepatient, an imminent voiding event predicted by the patient, or avoluntary voiding event to be undertaken by the patient. Patient inputmay also include indications of the efficacy of therapy delivered by atrial stimulator at various times during a stimulation trial.Additionally, as noted above, processor 302 may receive input from aclinician via user interface 306 that is related to the programming orinteraction with a trial stimulator according to this disclosure.

Telemetry module 308 supports wireless communication between a trialstimulator, e.g. trial stimulator 200 and external programmer 300 underthe control of processor 302. Telemetry module 308 may also beconfigured to communicate with another computing device via wirelesscommunication techniques, or direct communication through a wiredconnection. Telemetry module 308 may be substantially similar totelemetry module 210 described above with reference to trial stimulator200 of FIG. 5, providing wireless communication via an RF or proximalinductive medium. In some examples, telemetry module 308 may include anantenna, which may take on a variety of forms, such as an internal orexternal antenna. An external antenna that is coupled to programmer 300may correspond to a programming head that may be placed over trialstimulator 200. Examples of local wireless communication techniques thatmay be employed to facilitate communication between programmer 300 andanother computing device include RF communication according to IEEE802.11 or Bluetooth specification sets, infrared communication, e.g.,according to an IrDA standard, or other standard or proprietarytelemetry protocols. In this manner, other external devices may becapable of communicating with programmer 300 without needing toestablish a secure wireless connection.

Power source 310 of programmer 300 delivers operating power to thecomponents of programmer 300. Power source 310 may include a battery,for example a rechargeable or primary source battery. Recharging may beaccomplished by using an alternating current (AC) outlet or throughproximal inductive interaction between an external charger and aninductive charging coil within programmer 300.

FIG. 7 is a flowchart illustrating an example method of using adisposable trial stimulator according to this disclosure. The method ofFIG. 7 includes sterilizing a percutaneous stimulation lead and a trialstimulator (400), implanting the percutaneous stimulation lead todeliver stimulation to a target tissue location (402), connecting thepercutaneous stimulation lead to the disposable trial stimulator (404),programming the trial stimulator to deliver stimulation via thepercutaneous stimulation lead (406), delivering stimulation to thetarget tissue location via the percutaneous stimulation lead with thetrial stimulator for a trial period of time (408), and disposing of thetrial stimulator after expiration of the trial period of time (410).

The example method of claim 7 includes sterilizing a percutaneousstimulation lead and a trial stimulator (400). For example, trialstimulator 16 and lead 18 of system 10 of FIG. 1 or trial stimulator 102and leads 106 of system 100 of FIG. 3 may be sterilized. Additionally,in systems like system 10 of FIG. 1, a lead extension like leadextension 22 may also be sterilized along with trial stimulator 16 andlead 18. As noted above, in contrast to current trial stimulationsystems including reusable trial stimulators, because example trialstimulators according to this disclosure are configured to be disposedof after a single trial, the trial stimulator and any leads connectedthereto may be sterilized prior to implanting the leads. Sterilizationof the lead and the disposable trial stimulator in examples according tothis disclosure may function to maintain the integrity of the sterilefield during surgery and may therefore reduce the risk of potentiallyharmful microbes traveling into or out of the sterile field, which may,in turn, reduce the risk of complications such as contamination and/orinfection. Although the example method of FIG. 7 recites sterilizing andimplanting one lead, it is noted that in other examples according tothis disclosure multiple leads may be sterilized, implanted, and coupledto a disposable trial stimulator.

In addition to sterilizing a percutaneous stimulation lead and a trialstimulator (400), the method of FIG. 7 includes implanting thepercutaneous stimulation lead to deliver stimulation to a target tissuelocation (402). For example, in system 10 configured to deliver pelvicfloor stimulation to treat one of a number of conditions includingurgency and urinary incontinence, lead 28 may be implanted in patient 14through incision 28 and subcutaneously tunneled to arrange electrodes 20adjacent a pelvic floor nerve or nerves. In another example like system100 directed to treating chronic pain via SCS, leads 16 may be implantedin patient 104 through incision 110 to arrange electrodes on the leadsadjacent spinal cord 112.

The example method of FIG. 7 includes connecting the percutaneousstimulation lead to the disposable trial stimulator (404). In oneexample, the lead is connected directly to the disposable trialstimulator via a lead coupler integral with the trial stimulator. Thelead coupler may be configured to connect a plurality of types ofpercutaneous stimulation leads directly to the trial stimulator withoutany intervening lead connection devices. For example, example disposabletrial stimulator 102 of FIGS. 3 and 4A and 4B is connected to lead 106including four electrodes 126A-126D via lead coupler 122. Top half 120 aof housing 120 includes two lead coupler doors 128 and 130, which areconfigured to pivot open to expose lead coupler 122.

Lead coupler 122 of trial stimulator 102 is configured to connect up tofour stimulation leads to the disposable stimulator. Opening doors 128and 130 exposes six slots 134A-134F (collectively “slots 134”) includedin lead coupler 122. Slots 134 may be substantially the same andconfigured to receive the same type of stimulation leads or, in otherexamples, one or more of slots 134 may be different from one another andconfigured to receive different types of stimulation leads, e.g. slots134A and 134F with eight contacts are different than slots 134B-134Ewith four contacts. Each of slots 134 of lead coupler 122 of trialstimulator 102 is configured to connect one stimulation lead tostimulator 102. For example, percutaneous stimulation lead 106 isconnected directly to trial stimulator without any intervening leadconnection devices via slot 134D of lead coupler 122. Each of slots 134may include one or more electrical contacts, like contact 136illustrated with reference to slot 134D in FIG. 4A. Stimulation leads,like lead 106 may be press fit into slots 134, e.g., press fit latterlyinto slots 134 when doors 128 and 130 are open and may be configuredwith exposed electrical conductors arranged along the end of the leadreceived by the slots, e.g. the proximal end of the lead, such that thelead conductors contact the electrical contacts in slots 134.Stimulation leads, like lead 106 may thus be electrically connected totrial stimulator 102 such that stimulator 102 may deliver stimulationtherapy or sense various parameters related to a patient via electrodesarranged at the distal end of the lead, e.g. electrodes 126A-126D andconnected to the lead conductors contacting the electrical contacts ofslots 134.

In another example, the percutaneous stimulation lead may be connectedto the trial stimulator (404) indirectly. For example, lead 18 of system10 of FIG. 1 may be connected to lead extension 22 via adaptor 26 andlead extension 22 may be connected to trial stimulator 16.

In some examples according to this disclosure, the trial stimulation towhich the percutaneous lead(s) is connected (404) in the example methodof FIG. 7 includes a single user interface integral with the trialstimulator. For example, trial stimulator 16 of FIG. 1 includes button30 and trial stimulator 102 of FIG. 3 includes button 124 as the singleuser interface integral with the respective disposable trial stimulatorsaccording to this disclosure. The single user interface, e.g. userinterface 212 of trial stimulator 200 of FIG. 5 may be configured tocause stimulator 200 to be capable of wireless communications with anelectronic programmer and to turn off stimulation being delivered by thetrial stimulator in the manner described above with reference to FIG. 5.

In addition to connecting the percutaneous stimulation lead to thedisposable trial stimulator (404), the example method of FIG. 7 includesprogramming the trial stimulator to deliver stimulation via thepercutaneous stimulation lead (406) and delivering stimulation to thetarget tissue location via the percutaneous stimulation lead with thetrial stimulator for a trial period of time (408). In some examplesaccording to this disclosure programming of a disposable trialstimulator, including intraoperative set-up and programming of suchdevices will be executed by an electronic programming device viawireless communications between the programmer and stimulator. In otherwords. programming of disposable programming devices according to thisdisclosure does not necessitate any direct interaction with userinterface controls or other I/O devices integral with the stimulator andthus the stimulator may be kept within the sterile field during surgery.In one example, after communications between trial stimulator 16 andprogrammer 24 have been initiated, e.g., by pressing button 30, trialstimulator 16 may be programmed to delivery pelvic floor stimulation topatient 14 via electrodes 20 on lead 18 by programmer 24. In anotherexample, trial stimulator 102 may be programmed to deliver SCS topatient 104 via electrodes on leads 106 by programmer 108, in theexample of FIG. 3.

After the trial stimulator has been set-up and programmed, stimulationis delivered by the stimulator to the target tissue location via thepercutaneous stimulation lead for a trial period of time (408). Forexample, processor 204 of trial stimulator 200 controls therapy deliverymodule 208 to deliver therapy via one or more of electrodes 218 on lead216. In one example, therapy delivery module 208 of example disposabletrial stimulator 200 may be configured to deliver current controlledstimulation via various electrodes of one or more electrode arrays,including, e.g. different combinations of electrodes 218 on lead 216. Inone example, therapy delivery module 208 includes a stimulationgenerator including a voltage supply, a stimulation control module, anda current regulator array and is configured to drive more than oneelectrode combination at one time. Additionally, as described above, inone example, therapy delivery module 208 may be configured to simulatevoltage controlled stimulation with a current controlled stimulationengine. For example, therapy delivery module 208 may be configured tovary the current level of the stimulation delivered via electrodes 218on lead 216 based on changing impedance levels in the target tissuebeing stimulated in order to deliver stimulation at a substantiallyconstant voltage amplitude.

Chronic implantation of a pulse generator and lead for deliveringstimulation therapy to a patient may be preceded by a trial period oftime. The trial period ordinarily has a prescribed maximum duration, butsometimes is exceeded by the patient or the physician. During the trialperiod, a clinician evaluates the efficacy of stimulation in alleviatingthe patient's disorder to determine whether the patient is a goodcandidate for chronic implantation. Examples according to thisdisclosure, including the example method of FIG. 7, are directed todelivering electrical stimulation therapy via a disposable trialstimulator during a trial stimulation period of time, which may last,e.g., 1-3 weeks.

After expiration of the trial period of time, the example method of FIG.7 includes disposing of the trial stimulator (410). For example, lead 16of system 10 of FIG. 1 may be disconnected from trial stimulator 16 andremoved from patient 14 or continue to be employed in additional trialsor as part of a chronic stimulation system. Trial stimulator 16,however, is disposed of after the single stimulation trial of patient14. Similarly, in one example, lead 106 of system 100 of FIG. 3 may bedisconnected from trial stimulator 102 and removed from patient 104 oremployed in additional trials or as part of a chronic stimulationsystem. Trial stimulator 102, however, is disposed of after the singlestimulation trial of patient 104. Disposal of a trial stimulatoraccording to this disclosure generally refers to not reusing thestimulator beyond a single stimulation trial with one patient. Thus,disposal may include discarding of the trial stimulator completely ormay include partially or completely recycling the trial stimulator andcomponents thereof.

As described above, examples according to this disclosure includedevices for securing a disposable trial stimulator to the body of apatient, which may function to improve the durability of a trialstimulation system during the trial period and reduce the risk of damageor malfunction to the system due to lead/electrode dislocation and/oroff-label uses like showering or bathing with the trial stimulator stillsecured to the body. FIGS. 8A-8C and 9A-9C are conceptual diagramsillustrating two different example systems for securing a disposabletrial stimulator to the body of a patient. In general, however, a systemfor securing a disposable trial stimulator to a body of a patientincludes a patch and a holster. The patch includes a first major surfaceat least partially covered with an adhesive configured to adhere thepatch to the body of the patient. The holster is connected to a secondmajor surface of the patch. The holster is configured to receive thetrial stimulator.

FIGS. 8A-8C are conceptual diagrams illustrating example system 500 forsecuring a disposable trial stimulator to the body of a patient. In oneexample, system 500 of FIGS. 8A-8C may be employed to secure trialstimulator 16 of FIGS. 1-2C to the lower back of patient 14. System 500includes patch 502 and holster 504. Patch 502 includes first majorsurface 506, which may be at least partially covered with an adhesiveconfigured to adhere the patch to the body of a patient, e.g., to thelower back of patient 14. Holster 504 is connected to second majorsurface 508 of patch 502 and is configured to receive a disposable trialstimulator according to this disclosure, including, e.g., trialstimulator 16.

Patch 502 is configured to adhere to the skin of a patient. As such,first major surface 506 is at least partially covered with a medicalgrade adhesive. In one example, first major surface 506 is covered withan acrylic pressure-sensitive adhesive. In one example, the acrylicadhesive employed for first major surface 506 of patch 502 may besimilar to the adhesive used on the MED 5719 single coated whiteembossed non-woven tape manufactured by Avery Dennison of Painesville,Ohio. Patch 502 may be fabricated from a number of materials. In oneexample, patch 502 comprises a polyethylene terephthalate (PET)non-woven material.

Holster 504 is connected to second major surface 508 of patch 502. Asillustrated in the example of FIGS. 8A-8C, holster 504 may be adhereddirectly to patch 502 with an adhesive between second major wall 510B ofholster 504 and second major surface 508 of patch 502. In one example,holster 504 is adhered to patch 502 with double sided tape. For example,holster 504 may be adhered to patch 502 with double sided tape with afirst adhesive configured to engage second major surface 508 of patch502 and a second adhesive configured to engage second major wall 510B ofholster 504. In one example, holster 504 is adhered to patch 502 withdouble coated tape 9731 manufactured by 3M Company of St. Paul, Minn.,which includes a silicone pressure sensitive adhesive coated on one sideof a polyester film carrier and a high performance acrylic adhesivecoated on the other side of the carrier.

In other examples, holster 504, or another holster according to thisdisclosure may be connected to patch 502 indirectly. For example, aflexible pouch may be connected to patch 502, e.g. using an adhesive.Holster 504 may then be received in the pouch to secure the holster andthe trial stimulator held therein to the body of a patient. In suchexamples, patch 502 and holster 504 may remain separable.

In FIGS. 8A-8C, holster 504 includes first and second major walls 510Aand 510B, respectively, and four minor walls 512A-512D. First and secondmajor walls 510A and 510B are generally rectangular planar walls, eachof which includes four edges. Minor walls 512A-512D protrudeperpendicular from each of the four edges of second major wall 510B toconnect to the four edges of first major wall 510A. First and secondmajor walls 510A and 510B are parallel and offset from each other byminor walls 512A-512D.

First major wall 510A includes aperture 514, which is sized to permit atrial simulator according to this disclosure, like, e.g., trialstimulator 16 to be inserted into holster 504. Aperture 514 is sizedsuch that a majority of first major wall 510A of holster 504 is open forinsertion of a trial stimulator, but a rim 516 remains around theperimeter of first major wall 510A that helps to hold the trialstimulator in holster 504. Aperture 514 is sized such that it may exposeuser interface or other I/O devices of a trial stimulator received byholster 504. For example, aperture 514 is sized to expose button 30 oftrial stimulator 16 of FIG. 1.

Second major wall 510B of holster 504 includes grooves 518. Grooves 518terminate at slots 520 in minor walls 512A-512D. Grooves 518 and slots520 are configured to channel water and other moisture off of a trialstimulator secured by system 500 and out of holster 504. In the exampleof FIGS. 8A-8C, holster 504 includes five grooves in second major wall510B, three extending perpendicular to and between minor walls 512A and512C and two extending perpendicular to and between minor walls 512B and512D. In other examples, however, a holster for receiving and securing atrial stimulator according to this disclosure may include more or fewergrooves such as grooves 518 (see, e.g., FIGS. 9A-9C).

Minor wall 512B of holster 504 includes aperture 522, which may beconfigured to accommodate a lead extension that is coupled to a trialstimulator secured by system 500 in holster 504. For example, aperture522 may be shaped and sized to accommodate lead extension 22 that iscoupled to trial stimulator 16 and includes lead adaptor 26 that isconfigured to connect extension 22 to a lead, like, e.g., lead 18. Inthe example of FIGS. 8A-8C, holster 504 also includes pad 524, which maybe configured to be interposed between lead extension 22 and patch 502to prevent or reduce the risk of extension 22 causing irritation of orsores on the skin of a patient.

In one example, holster 504 is a resilient material that is configuredto elastically deform in order to insert a trial stimulator into holster504 including stretching rim 516 of first major wall 510A around theperimeter of the trial stimulator. Holster 504 may be fabricated from avariety of materials, including, e.g., a variety of polymers. Forexample, holster 504 may be fabricated from a variety of plastics orelastomers. In one example, holster 504 is fabricated from a Class VIsilicone with 40 A+/−5 durometer hardness.

FIGS. 9A-9C are conceptual diagrams illustrating another example system600 for securing a disposable trial stimulator to the body of a patient.In one example, system 600 of FIGS. 9A-9C may be employed to securetrial stimulator 102 of FIGS. 3, 4A and 4B to the lower back of patient104. System 600 includes patch 602 and holster 604. Patch 602 includesfirst major surface 606, which may be at least partially covered with anadhesive configured to adhere the patch to the body of a patient, e.g.,to the lower back of patient 104. Holster 604 is connected to secondmajor surface 608 of patch 602 and is configured to receive a disposabletrial stimulator according to this disclosure, including, e.g., trialstimulator 102.

System 600 may be substantially similar to system 500 of FIGS. 8A-8C,except in the geometric configuration of holster 604, which isconfigured to receive a different disposable trial stimulator accordingto this disclosure, e.g. trial stimulator 102. For example, thematerials of patch 602 and holster 604, the manner in which holster 604is connected to second major surface 608 of patch 602, the adhesivesused for adhering first major surface 606 of patch 602 to the body of apatient and adhering holster 604 to second major surface 608 of patch602 may be similar to such features described above with reference tosystem 500 of FIGS. 8A-8C.

In FIGS. 9A-9C, holster 604 includes first and second major walls 610Aand 610B, respectively, and four minor walls 612A-612D. First and secondmajor walls 610A and 610B are generally rectangular planar walls, eachof which includes four edges. Minor walls 612A-612D protrudeperpendicular from each of the four edges of second major wall 610B toconnect to the four edges of first major wall 610A. First and secondmajor walls 610A and 610B are parallel and offset from each other byminor walls 612A-612D.

Minor wall 612B of holster 604 includes aperture 614, which is sized topermit a trial simulator according to this disclosure, like, e.g., trialstimulator 102 to be inserted into holster 604. Aperture 614 is sizedsuch that a majority of minor wall 612B of holster 604 is open forinsertion of a trial stimulator, but a rim 616 remains around theperimeter of minor wall 612B that helps to hold the trial stimulator inholster 604.

In addition to allowing insertion of a trial stimulator, e.g. stimulator102 into holster 604, aperture 614 also functions to accommodate one ormore leads directly or indirectly coupled to holster 604. For example,leads 16 may be directly coupled to trial stimulator 102 via leadcoupler 122 integral with stimulator 102 through aperture 614 whenstimulator 102 is held within holster 604.

Second major wall 610B of holster 604 includes grooves 618. Grooves 618terminate at slots 620 in minor walls 612A-612D. Grooves 618 and slots620 are configured to channel water and other moister off of a trialstimulator secured by system 600 and out of holster 604. In the exampleof FIGS. 9A-9C, holster 604 includes four grooves in second major wall610B, two extending perpendicular to and between minor walls 612A and612C and two extending perpendicular to and between minor walls 612B and612D. In other examples, however, a holster for receiving and securing atrial stimulator according to this disclosure may include more or fewergrooves such as grooves 618 (see, e.g., FIGS. 8A-8C).

First major wall 610A of holster 604 includes aperture 618. Aperture 618may be shaped and sized to expose user interface or other I/O devices ofa trial stimulator received by holster 604. For example, aperture 618 issized to expose button 124 of trial stimulator 102 of FIG. 3. Holster504 and/or holster 604 of FIGS. 8A-8C and 9A-9C, respectively, mayinclude additional apertures to accommodate other interfaces to therespective trial stimulators held by each holster. For example, holster504 and/or holster 604 may include one or more additional apertures inthe major walls or minor walls of the holsters that are sized and shapedto accommodate various I/O devices, including, e.g., a receptacleconfigured to receive a computer readable storage medium.

FIG. 10 is a flowchart illustrating an example method of securing adisposable trial stimulator to the body of a patient. The method of FIG.10 includes implanting a percutaneous stimulation lead to deliverstimulation to a target tissue location (700), adhering a first majorsurface of a patch at least partially covered with an adhesive to thebody of the patient (702). A holster is connected to a second majorsurface of the patch. The holster is configured to receive the trialstimulator. The method of FIG. 10 also includes inserting the trialstimulator into the holster (704) and connecting the percutaneousstimulation lead to the trial stimulator (706).

For brevity, the example method of FIG. 10 will be described in thecontext of securing trial stimulator 16 of FIG. 1 to the body of patient14 employing system 500 of FIGS. 8A-8C. However, in other examples, themethod of FIG. 10 may be employed to secure other disposable trialstimulators to the body of a patient. For example, the method of FIG. 10may be employed to secure trial stimulator 102 of FIG. 3 to the body ofpatient 104 using system 600 of FIGS. 9A-9C.

The method of FIG. 10 includes implanting the percutaneous stimulationlead to deliver stimulation to a target tissue location (700). Forexample, in system 10 configured to deliver pelvic floor stimulation totreat one of a number of conditions including urgency and urinaryincontinence, lead 28 may be implanted in patient 14 through incision 28and subcutaneously tunneled to arrange electrodes 20 adjacent a pelvicfloor nerve or nerves.

The example method of FIG. 10 also includes adhering a first majorsurface of a patch at least partially covered with an adhesive to thebody of the patient (702). In one example, patch 502 is adhered to thelower back of patient 14. For example, patch 502 may be packaged with athin plastic film covering the adhesive at least partially coveringfirst major surface 506 of patch 502. A clinician may remove the plasticfilm from first major surface 506 of patch 502 and press patch 502against the skin of patient 14, thereby activating thepressure-sensitive acrylic adhesive covering first major surface 506 andadhering system 500 to the patient's body.

In addition to adhering a first major surface of a patch at leastpartially covered with an adhesive to the body of the patient (702), themethod of FIG. 10 also includes inserting the trial stimulator into theholster (704). In one example, trial stimulator 16 is inserted intoholster 504. For example, trial stimulator 16 may be inserted throughaperture 514 such that when received in holster 504 button 30 is exposedby aperture 514 and coupler 32 is aligned with aperture 522 in minorwall 512B. Holster 504 may be fabricated from a resilient material thatis configured to be elastically, e.g. reversibly deformed includingstretching rim 516 of first major wall 510A around the perimeter oftrial stimulator 16. After holster 504 has been stretched to inserttrial stimulator 16 therein, rim 516 around the perimeter of first majorwall 510A that helps to hold the trial stimulator in holster 504regardless of the orientation of holster 504 or system 500 as a whole.

The method of FIG. 10 also includes connecting the percutaneousstimulation lead to the disposable trial stimulator (706). In oneexample, lead 18 is connected to lead extension 22 via adaptor 26 andlead extension 22 is connected to trial stimulator 16. Aperture 522 inminor wall 512B of holster 504 is sized and shaped to accommodate leadextension 22. In another example, a lead may be connected directly tothe disposable trial stimulator held in a holster according to thisdisclosure via a lead coupler integral with the trial stimulator. Thelead coupler may be configured to connect a plurality of types ofpercutaneous stimulation leads directly to the trial stimulator withoutany intervening lead connection devices.

Any combination of the foregoing systems and devices may be packaged asa kit. For example, system 10 of FIG. 1 and system 100 of FIG. 3 may bepackaged as a kit including at least one lead, and, as appropriate, atleast one lead extension, and at least one trial stimulator.Additionally, trial stimulation systems according to this disclosure maybe packaged as a kit with systems for securing trial stimulators to thebody of a patient, including, e.g. systems like system 500 of FIGS.8A-8C and system 600 of FIGS. 9A-9C. As such, in one example, at leastone of each of trial stimulator 16, lead extension 22, lead 18, andsystem 500 including patch 502 and holster 504 may be packaged as a kit.In another example, at least one of each of trial stimulator 102, lead16, and system 600 including patch 602 and holster 604 may be packagedas a kit. In some examples, systems for securing trial stimulators tothe body of a patient, including, e.g. systems like system 500 of FIGS.8A-8C and system 600 of FIGS. 9A-9C may be packaged on their ownseparate from the trial stimulation system. In some examples, kits mayinclude multiple leads and/or lead extensions including the same ordifferent types of leads and extensions.

The techniques described in this disclosure may be implemented inhardware, software, firmware, or any combination thereof. In particular,the techniques may be implemented in a hardware device, such as awireless communication device or network device, either of which mayinclude software and/or firmware to support the implementation. Forportions implemented in software, the techniques may be realized in partby a computer-readable medium comprising program code containinginstructions that, when executed, performs one or more of the methodsdescribed above. In this case, the computer readable medium may compriseRAM (e.g., synchronous dynamic random access memory (SDRAM)), ROM,NVRAM, EEPROM, FLASH memory, magnetic or optical data storage media, andthe like.

The program code may be executed by one or more processors, such as oneor more DSPs, general purpose microprocessors, ASICs, FPGAs, or otherequivalent integrated or discrete logic circuitry. In this sense, thetechniques are implemented in hardware, whether implemented entirely inhardware or in hardware such as a processor executing computer-readablecode. Accordingly, the term “processor,” as used herein may refer to anyof the foregoing structure or any other structure suitable forimplementation of the techniques described herein.

Many examples of the disclosure have been described. These and otherexamples are within the scope of the following claims. Variousmodifications may be made without departing from the scope of theclaims.

The invention claimed is:
 1. A disposable external trial electricalstimulator comprising: a therapy delivery module configured to deliverelectrical stimulation via at least one percutaneous stimulation leadconfigured to be connected to the disposable external trial stimulator;a lead coupler configured to connect a plurality of types ofpercutaneous stimulation leads configured to be coupled to thedisposable trial stimulator directly to the disposable external trialstimulator without any intervening lead connection devices, the at leastone percutaneous stimulation lead configured to be connected to thedisposable external trial stimulator being one type of percutaneousstimulation lead of the plurality of types of percutaneous stimulationleads; a lead coupler door comprising a portion of an exterior wall ofthe disposable external trial stimulator and configured to expose thelead coupler when opened; and a processor configured to: control thetherapy delivery module to deliver the electrical stimulation via the atleast one percutaneous stimulation lead; automatically detect, when theat least one percutaneous stimulation lead is connected to thedisposable external trial stimulator, the at least one percutaneousstimulation lead as the one type of percutaneous stimulation leadinstead of another type of percutaneous stimulation lead of theplurality of types of percutaneous stimulation leads; automatically,based on the detected one type of percutaneous stimulation leadconnected to the trial stimulator, perform one or more of the following:(1) limit one or more stimulation programming options available to aprogrammer, (2) limit one or more stimulation parameter values, or (3)select one or more different programs according to stimulation that thetherapy delivery module can deliver via the detected one type ofpercutaneous stimulation lead; detect when the lead coupler door isopen; and responsive to detecting that the lead coupler door is open,automatically, and without user interaction, control the therapydelivery module to cease delivery of stimulation, wherein the disposableexternal trial stimulator is sterilized.
 2. The disposable externaltrial stimulator of claim 1, further comprising a housing that isconfigured to resist ingress of liquid into an interior chamber definedby the housing.
 3. The disposable external trial stimulator of claim 2,wherein the housing comprises a first half and a second half connectedto one another via an ultrasonic weld configured to resist ingress ofliquid into the interior chamber defined by the housing.
 4. Thedisposable external trial stimulator of claim 1, wherein the therapydelivery module comprises a stimulation generator configured to delivercurrent controlled stimulation via one or more electrodes connected tothe at least one percutaneous stimulation lead.
 5. The disposableexternal trial stimulator of claim 4, wherein the therapy deliverymodule is configured to simulate voltage controlled stimulation with thecurrent controlled stimulation delivered by the stimulation generator.6. The disposable external trial stimulator of claim 1, wherein theprocessor is configured to automatically, and without user interaction,control the therapy delivery module to cease delivery of stimulationwhen the at least one percutaneous stimulation lead is disconnected fromthe disposable external trial stimulator.
 7. The disposable externaltrial stimulator of claim 1, further comprising at least onecommercially available primary cell battery connected to and configuredto power the disposable external trial stimulator.
 8. The disposableexternal trial stimulator of claim 7, wherein the at least onecommercially available primary cell battery comprises at least one AAAAbattery.
 9. The disposable external trial stimulator of claim 1, whereinthe processor is configured to: monitor stimulation intensity deliveredby the disposable external trial stimulator; and generate an alert whenthe stimulation intensity delivered by the therapy delivery module doesnot equal a programmed stimulation intensity.
 10. The disposableexternal trial stimulator of claim 9, wherein the processor isconfigured to control the therapy delivery module to cease delivery ofstimulation when the stimulation intensity does not equal a programmedstimulation intensity.
 11. The disposable external trial stimulator ofclaim 1, further comprising a power management module configured tooperate the disposable external trial stimulator in a plurality of powerconsumption modes, wherein the plurality of power consumption modescomprises a shelf mode, and wherein the power management module isconfigured to limit one or more components of the disposable externaltrial stimulator to which power is supplied in the shelf mode.
 12. Thedisposable external trial stimulator of claim 1, further comprising alead retention clip configured to hold the at least one percutaneousstimulation lead in place when the lead coupler door is opened.
 13. Thedisposable external trial stimulator of claim 1, wherein the therapydelivery module is configured to deliver stimulation via the at leastone percutaneous stimulation lead while one or more additionalpercutaneous stimulation leads are being connected to the disposableexternal trial stimulator via the lead coupler.
 14. The disposableexternal trial stimulator of claim 1, further comprising a single userinterface integral with the disposable external trial stimulator,wherein the user interface is configured to control the disposableexternal trial stimulator to be capable of wireless communications withan electronic programming device and to turn off stimulation beingdelivered by the disposable external trial stimulator.
 15. Thedisposable external trial stimulator of claim 1, wherein the therapydelivery module is configured to deliver neurostimulation to a nervoussystem of a patient via the at least one percutaneous stimulation leadconnected to the external trial stimulator.
 16. The external trialstimulator of claim 1, wherein the processor is configured toautomatically detect the at least one percutaneous stimulation lead asthe one type of percutaneous stimulation lead by comparing a firstresistance of a conductor of the at least one percutaneous stimulationlead to a plurality of resistances associated with respectivepercutaneous stimulation lead types of the plurality of percutaneousstimulation lead types stored in a memory of the disposable externaltrial stimulator.
 17. The external trial stimulator of claim 1, whereinthe processor is configured to automatically detect the at least onepercutaneous stimulation lead as the one type of percutaneousstimulation lead by comparing a voltage drop across the disposableexternal trial stimulator and a conductor of the at least onepercutaneous stimulation lead to a plurality of voltage valuesassociated with respective percutaneous stimulation lead types of theplurality of percutaneous stimulation lead types stored in a memory ofthe external trial stimulator.
 18. The disposable external trialstimulator of claim 1, wherein the lead coupler is configured to connectto, and the processor is configured to detect, each type of percutaneousstimulation lead of the plurality of types of percutaneous stimulationleads that comprises at least one of a different number of contacts,contacts having different sizes, or contacts having different shapesthan other types of percutaneous stimulation leads of the plurality oftypes of percutaneous stimulation leads.
 19. A method comprising:implanting a percutaneous stimulation lead configured to be connected toa disposable external trial stimulator to deliver stimulation to atarget tissue location; connecting the percutaneous stimulation leaddirectly to the disposable external trial stimulator via a lead couplerintegral with the disposable external trial stimulator, wherein the leadcoupler is configured to connect a plurality of types of percutaneousstimulation leads configured to be coupled to the disposable trialstimulator directly to the disposable external trial stimulator withoutany intervening lead connection devices, the percutaneous stimulationlead configured to be connected to the disposable external trialstimulator being one type of percutaneous stimulation lead of theplurality of types of percutaneous stimulation leads; automaticallydetecting, by a processor of the disposable external trial stimulatorand when the percutaneous stimulation lead is connected to thedisposable external trial stimulator, the percutaneous stimulation leadas the one type of percutaneous stimulation lead instead of another typeof percutaneous stimulation lead of the plurality of types ofpercutaneous stimulation leads; automatically, by the processor of thedisposable external trial stimulator and based on the detected one typeof percutaneous stimulation lead connected to the trial stimulator,performing one or more of the following: (1) limiting one or morestimulation programming options available to a programmer, (2) limitingone or more stimulation parameter values, or (2) selecting one or moredifferent programs according to stimulation that the external trialstimulator can deliver via the detected one type of percutaneousstimulation lead; programming, with an electronic programming device,the disposable external trial stimulator to deliver stimulation via thepercutaneous stimulation lead, wherein the electronic programming deviceis configured to wirelessly communicate with the disposable externaltrial stimulator; delivering stimulation to the target tissue locationvia the percutaneous stimulation lead with the disposable external trialstimulator for a trial period of time; detecting, by the processor ofthe disposable external trial stimulator, that a lead coupler door isopen, the lead coupler door comprising a portion of an exterior wall ofthe disposable external trial stimulator and configured to expose thelead coupler when opened; responsive to detecting that the lead couplerdoor is open, automatically, by the processor of the disposable externaltrial stimulator and without user interaction, controlling thedisposable external trial stimulator to cease delivery of stimulation;and disposing of the disposable external trial stimulator afterexpiration of the trial period of time.
 20. The method of claim 19,further comprising sterilizing the percutaneous stimulation lead and thedisposable external trial stimulator prior to implanting thepercutaneous stimulation lead.
 21. The method of claim 19, furthercomprising: selecting a user interface integral with the disposableexternal trial stimulator after connecting the percutaneous stimulationlead to the disposable external trial stimulator; and initiating awireless communication session between the disposable external trialstimulator and the electronic programming device prior to programmingthe disposable external trial stimulator to deliver stimulation.
 22. Themethod of claim 19, further comprising: monitoring stimulation intensitydelivered by the disposable external trial stimulator via thepercutaneous stimulation lead; and generating an alert when thestimulation intensity delivered by the disposable external trialstimulator does not equal a programmed stimulation intensity.
 23. Themethod of claim 22, further comprising controlling the disposableexternal trial stimulator to cease delivery of stimulation when thestimulation intensity does not equal a programmed stimulation intensity.24. The method of claim 19, wherein the percutaneous stimulation leadcomprises a first percutaneous stimulation lead, and wherein the methodfurther comprises: connecting a second percutaneous stimulation lead tothe disposable external trial stimulator via the lead coupler; andcontinuing delivering stimulation to the target tissue location via thefirst percutaneous stimulation lead while the second percutaneousstimulation lead is being connected to the disposable external trialstimulator via the lead coupler.
 25. The method of claim 19, whereindelivering stimulation to the target tissue location via thepercutaneous stimulation lead with the disposable external trialstimulator comprises delivering neurostimulation to a nervous system ofa patient.
 26. A disposable external trial electrical stimulatorcomprising: a therapy delivery module configured to deliver electricalstimulation via at least one percutaneous stimulation lead configured tobe connected to the disposable external trial stimulator, wherein thedisposable external trial stimulator is sterilized; a lead couplerconfigured to connect the at least one percutaneous stimulation leaddirectly to the disposable external trial stimulator, wherein the leadcoupler is configured to connect a plurality of types of percutaneousstimulation leads configured to be coupled to the disposable trialstimulator directly to the disposable external trial stimulator withoutany intervening lead connection devices; a lead coupler door comprisinga portion of an exterior wall of the disposable external trialstimulator and configured to expose the lead coupler when opened; and aprocessor configured to: control the therapy delivery module to deliverthe electrical stimulation via the at least one percutaneous stimulationlead; detect when the lead coupler door is open; and responsive todetecting that the lead coupler door is open, automatically, and withoutuser interaction, control the therapy delivery module to cease deliveryof stimulation.
 27. The disposable external trial electrical stimulatorof claim 26, further comprising a lead retention clip configured to holdthe at least one percutaneous stimulation lead in place when the leadcoupler door is opened.